RA81 Disk Drive Service Manual

Out of curiosity, I looked for RA81 information on the internet. I found the following links: I created this document as there appears to be no on line version of the RA81 Service Manual.

EK-ORA81-SV-01

I own a copy of the Digital manual above. It has good sections on how to open up the drive and inspect the drive belt, lock or unlock the heads, and run the internal diagnostics. I cover that here, however the material presented is in this document is a significantly abridged version of the manual. This document does not include any of the figures or information on how to replace the various componets. This document is good for some basic trouble shooting, but I make no promises that my typing was accurate!

I originally purchased this manual ($60 US) around 1985 hoping to find out more about the MSCP protocol, but that information was not in the manual. The abridged information below is about all I have the energy to produce at this time.

DIAGNOSTICS

There is an allen screw near the front left corner of the top cover. Turning this a half turn releases the cover like a car's hood. It hings in the back. You can lift it up to access the logic boards and the RS232 diagnostics port. Note that there are 8 diagnostics leds at the front of the bottom logic board (microprocessor) which can be viewed with this cover open. The diagnostics port is a male DB25 connector, 300 baud on a VT100 works fine (manual says any EIA compatible terminal is ok). Apparently field service had a little hand held terminal that drew +5V power from the 3 pin connector behind the DB25.

The eight diagnostic leds at the front of the microprocessor board represent the bits of a diagnostic byte. These error and diagnostic codes are described in the detailed test descriptions (Appendix D) and summarized in Appendix E.

The recommended sequence is to power up the drive with all push buttons in the out position (RUN/STOP and ports A & B). When power is applied the drive runs a power-up test sequence. The front pannel lights should turn on during this sequence and then go out after 3-4 seconds indicating successful completion. Appendix F provides a fault table mapping if any of the lights on the front pannel remain on after this test.

If the port switches are in the out position per above the drive next performs the "idle loop test" which takes about 30 seconds. During this test the diagnositic leds display 0xE7. Pushing either RUN/STOP or either port switch will stop this test. Port switches cancel the test and exit diagnostic mode. Pushing RUN/STOP again will spin the drive down and the idle loop test will resume after about 10 seconds. If a terminal is connected during this sequence the results of each test run are shown as they complete:
"%RA81-COMPLETED TEST: SUBTEST:xx"

After the idle loop test completes, press ^C (control C) on the terminal to obtain the "RA81>" prompt. On my system its there already if one had the terminal connected during the startup sequence, guess ^C is an attention flag. At this point the following commands my be given:


RUN DIAGNOSTICS 
	Runs a series of diagnostics to check out the
	drive, one set run if the drive is not spun up.
	On completion the "RA81>" prompt is displayed.
	Spin the drive up with the RUN/STOP switch to
	get the second full series of diagnostics.  If
	it passes both of these you are probably in good
	shape.
RUN SEEK
	Perform with disk spun up.  Prompts user for
	a cylinder (max = 1257) and group (max = 13)
	a seeks to that location.
RUN RECALIBRATE
	Perform with disk spun up. Position and hold heads
	over track 0 for at least one rotation.
RUN READ/WRITE
	Perform with disk spun up. Execute the entire
	READ/WRITE series of tests.
RUN SERVO
	Perform with disk spun up, excercises the servo.
RUN INTERFACE
	Perform with disk spun down, checks disk interface.
RUN ALTERNATE
	Perform with disk spun up.  Prompts for a starting
	and ending cylinder and performs alternating seeks.
RUN RANDOM
	Perform with disk spun up, performs a random
	series of seeks (no user input required).
RUN INCREMENTAL
	Perform with disk spun up.  Prompts for a starting
	and ending cylinder.  Performs a seek to each 
	cylinder in this range and does a recalibrate on
	that cylinder.
RUN DIAGNOSTIC TEST=XX
	Just performs diagnostic test XX
HELP
	Displays a list of all diagnostic and utility commands
SET DIAGNOSTIC LOOP XXXX
	Controls the mode in which "RUN DIAG TEST=xx" operates.
	Options are: 
		"ON" - loop in test until a ^C is entered
		"OFF" - run test once (default)
		"HALT" - continue to run test until it faults
SET TERMINAL SPEED=XXXX
	Set baud rate, options are 300 (default) and 1200
SHOW RADIX
	Display radix used: decimal for all but memory
	addresses, dumps, and error codes which are in hex.
SHOW VERSION
	Display microcode, hardware revision and SDI revision
SHOW DEVICE
	Display drive serial number and unit number
SHOW TERMINAL SPEED
	Display baud rate (how can you enter this command
        or see this message if you don't know?)
SHOW DIAGNOSTIC LOOP
	Display current loop mode (see SET DIAG LOOP)
SHOW DIAGNOSTIC FAULTS
	Display the last 16 HEX fault codes
SHOW DIAGNOSTIC STATUS XXXX
	Display up to 32 bytes of diagnostic RAM
	XXXX may be MASTER or SLAVE indicating which
	processor's memory is accessed
SHOW DIAGNOSTIC MEMORY XXXX=aaaa
	Dump 32 bytes of diagnostic memory
	XXXX may be MASTER or SLAVE per above
	aaaa is hex starting address in memory
EXIT
	Exit diagnostic mode, go to drive offline state.
	A ^Z (control Z) or pushing either PORT button
	will also cause an Exit.
The 2nd word (if there is one) in all the commands above may be abbreviated to the first 4 letters. All operations display the "RA81>" prompt on completion, indicating its ready for a new command.

MAINTENANCE

The entire front of the unit is an air intake, behind the bezel is a foam air filter which can be cleaned or replaced. Just below and to the left of the front pannel buttons is a small door latch that you press up to allow this door to swind down and open to access the filter.

The logic board enclosure and front pannel are also hinged at the back and can be raised to access the drive belt and winchester drive. The release is at the bottom center of the front bezel, its a push button which one presses with a screw driver cause its only about 3/16" wide and 1/2" tall. Page 2-13 of the manual has a picture of the drive with the drive logic chassis raised to access the physical drive. It shows a "positioner locking arm" near the front middle on the winchester drive. You can lock and unlock the head positioner with this, I believe one is supposed to lock this for shipping (the manual never says). A "belt tension lever" is also shown. The engaged position is with the lever horizontal and pointing toward the front of the case. Release is horizontal and pointing toward the back of the case. I find no mention of this in the manual, but again one assumes one can releave tension on the belt for storage.

Periodically one should check the drive belt tension. It can stretch with time and use. There is a micro switch in there somewhere which prevents it from spinning up if the belt is too loose. The adjustment screw is near the bottom and in front of the drive motor, just behind the right rear mounting bolt for the winchester. Its a hex screw and locking nut which point toward the front of the case. Its a little hard to describe without a picture, but to the right of this adjusting screw is a brass colored slider in a rail assembly. There is an L shaped metal bracket inserted in this rail assembly near the head of the adjusting screw. The end of the brass colored slider is supposed to line up with corner of this L bracket and be visible through the slot in the middle of the bracket. I haven't tried this yet.... (see figures in chapter 3).

APPENDIX B DIAGNOSTIC SEQUENCE LISTS

Test sequences make up many of the diagnostics that are executed using the terminal. There are also several automatically run tests that are sequences. This appendix lists the various test sequences with the subtest names and hexadecimal codes.

NOTE The last 4 tests in the spin-up sequence are not executed if the drive is in an on-line state when the RUN/STOP switch is pushed. The last four tests comprise the read/write sequence (test 13).

Table B-1 Diagnostic Sequence Lists  

Test Code   Name 

Hardcore Sequence (run on power-up) 

      Master RAM Test
01    Master ROM Check
OB    Master RAM Timer Test
03    3-Board Bus Test 
      UART Test  
      Slave RAM Test 
19    Slave ROM Check Test 

Drive Idle Loop Sequence (same as test 18) 

01    Master ROM Check
O7    Head Select MUX Test
O8    Sector Byte Counter Test
0B    Master RAM Timer Test
03    3-Board Bus Test
19    Slave ROM Check
1B    PLO Test
1A    Slave Communication Bus Test   
1C    Servo Sanity Timer Test
1D    ADC Test
1E    Positioner Loop Test
1F    Velocity Loop Test
20    Track Counter Test

Spinup Sequence 

1B    PLO Test
1C    Servo Sanity Timer Test
1D    ADC/DAC Test
1E    Positioner Loop Test
1F    Velocity Loop Test
20    Track Counter Test
OA    Stream Test
OF    Read Check Test
10    Write Check Test
OE    Read/Write Force Fault Test 

Entire Drive Checkout, Spun Down (same as test 17) 

02    Master LED Check
01    Master ROM Check
07    Head Select MUX Test
08    Sector Byte Counter Test
0B    Master RAM Timer Test
0D    PCB Wrap Test
19    Slave ROM Check
1B    Servo PLO Check
1C    Servo Sanity Timer Test
1D    ADC/DAC Test
1E    Positioner Loop Test
1F    Velocity Loop Test
20    Track Counter Test

Entire Drive Checkout, Spun Up (same as test 16) 

02    Master LED Check 
01    Master ROM Check 
07    Head Select MUX Test 
08    Sector Byte Counter Test 
0B    Master RAM Timer Test 
03    Three-Board Bus Test 
19    Slave ROM Check Test 
1B    PLO Test 
1C    Servo Sanity Timer Test 
1D    ADC/DAC Test 
1E    Positioner Loop Test 
1F    Velocity Loop Test 
20    Track Counter Test 
21    Servo Slow Seek Test 
22    Guard Band Detect Test 
25    Random Seek Test 
26    Seek-Seek Test (Default Mode) 
27    Incremental Seek Test (Default Mode) 
0A    Stream Test 
0F    Read Check Test 
10    Write Check Test 
0E    Read/Write Force Fault Test 
2A    Servo Recalibration 

Hardcore Sequence (same as test 12) 
02    LED Check Master 
01    ROM Check 
07    Head Select MUX Test 
0B    Master RAM Timer Test 
03    Three-Board Bus Test 

Read/Write Sequence (same as test 13) 

OA    Stream Test 
0F    Read Check Test 
10    Write Check Test 
0E    Read/Write Fault Force Test

Servo Spinup Sequence (same as test 14) 

1B    PLO Test 
1C    Servo Sanity Timer Test
1D    ADC/DAC Test, 
1E    Positioner Loop Test
1F    Velocity Loop Test
20    Track Counter Test

Entire Servo Sequence (same as test 15)

19    Slave ROM Check 
1A    Slave Communication Bus Test 
1B    PLO Test 
1C    Servo Sanity Timer Test 
1D    ADC/DAC Test 
1E    Positioner Loop Test 
1F    Velocity Loop Test 
20    Track Counter Test 
21    Servo Slow Seek Test 
22    Guard Band Detect Test 
25    Random Seek Test 
26    Seek-Seek Test (Default Mode) 
27    Incremental Seek Test (Default Mode) 
2A    Servo Recalibration  

APPENDIX C SUBSYSTEM RUN DIAGNOSTICS


Table C-1 contains a list of the drive-resident tests that can be initiated 
by the present subsystem diagnostics through the SDI controller. 

Table C-1 Subsystem Run Diagnostics 
Test  Name
Code 
01   Master ROM Check 
02   Master LED Check 
03   Three-Board Bus Test 
04   Microprocessor-Only Bus Test 
06   Servo/Microprocessor Bus Test 
07   Head Select MUX Test 
08   Sector/Byte Counter Test 
0B   Master RAM Timer Test 
14   Servo Spinup Test Sequence 
15   Entire Servo Test Sequence 
18   Drive Idle Test Sequence 
19   Slave ROM Check Test 
1A   Slave Communication Bus Test 
1B   PLO Test 
1C   Servo Sanity Timer Test 
1D   ADC/DAC Test 
1E   Positioner Loop Test 
1F   Velocity Loop Test 
20   Track Counter Test 
21   Servo Slow Seek Test 
22   Guard Band Detect Test 
25   Random Seek Test 
26   Seek-Seek Test (Default Mode) 
27   Incremental Seek Test (Default Mode) 
28   Servo Outer Guard Band Seek Test 
29   Servo Inner Guard Band Verify Test 
2A   Servo Recalibration Test 

Any of the above-listed tests may be run under control of the host-resident 
diagnostics. These drive tests may be called in using the drive-resident 
diagnostic for the subsystem. This diagnostic consists of four parts. 
For a UDA50 subsystem, the host-resident diagnostic is CZUDCxx, part two. 
To call in one of the tests listed in Table C-1, use the following instructions 

1. Answer Y to the question CHANGE SW (L)? N 
2. Answer Y to the question ENTER MANUAL INTERVENTION MODE FOR SPECIAL
   DIAGNOSIS (L)? 
3. The diagnostic allows the drive to begin the drive idle loop test sequence. 
   Refer to the appropriate VAX or 11-family diagnostic listing for specific 
   directions. At the completion of the sequence, the following message is 
   printed: 
   TEST 2 MANUAL INTERVENTION ON UNIT x UDA AT 172150 DRIVE x
   TO WRITE AND READ MEMORY: 
        W DATA REGION OFFSET 
        R REGION OFFSET 
   TO RUN A DIAGNOSTIC: 
        D REGION 
   TO EXIT QUESTIONING: 
        E 
   DATA, REGION AND OFFSET ARE HEX VALUES. 
        (A) ? (Type in the D followed by the specific test number found 
               in Table C-1) 
        (A) ? (Type in another test number or an E to exit the questioning) 

A diagnostic error message is printed and the drive faults if an invalid test 
number is requested. Byte 14 of the status line (see paragraph 5.2. 1) contains 
the error code of 2B (invalid region specified). The diagnostic then requests 
a new test to be run. This causes the diagnostic to print another error message 
and the drive to execute another drive idle loop test sequence. At the 
completion of the test sequence, the test number question is once again asked 
and legitimate testing can be continued. 

NOTE Do not depress the FAULT light to obtain a specific fault code during this 
time. The only way to clear the fault if the FAULT light has been depressed is 
to ^C the diagnostic. 

Depressing a ^C exits testing from the system level and cuts off communications 
between the drive and the controller. Testing continues until the current test 
sequence is complete. This can result in an unwanted error code of 41 
(response timed out). This is also accompanied by a front panel display of an 
SDI error. Both of these faults may be ignored (under these circumstances only). 

APPENDIX D RA81 DIAGNOSTIC TEST DESCRIPTION


The following paragraphs describe the RA81 diagnostic tests that can be 
initiated by the user keying in the command RUN DIAG/TEST=xx. There are a 
total of 44 tests that can be requested. All test numbers shown are hexadecimal 
and all test results are displayed on the terminal as well as on the LEDs of 
the microprocessor module. A code of AA is displayed by the LEDs for all 
successful completions. Appendix E lists the test fault codes. 

D.1 TEST 0 (ENTIRE DRIVE SEQUENCE) 
The microcode executes a particular sequence of tests depending upon whether 
the drive is spun up or not. All errors reported correspond to the individual 
tests. See Appendix B for a list of the tests run in this sequence. 

D.2 TEST I (MASTER ROM TEST) 
This test checks the master ROM set for consistency and checksum. Errors 
associated with this test are: 80, 87, 8F, 97, 9F, A7, AF. 

D.3 TEST 2 (LED TEST) 
This test checks for proper operation of the LEDs. The test starts by lighting 
the least significant LED and rotates through the LEDs to the most significant. 
All the LEDs are then turned on. By observing successful completion of the 
test, the following assumptions can be made: 
1. No LED is broken 
2. No two LEDs are shorted together 
3. The LEDs are operating correctly 
4. The LED decode hardware is operating correctly 
5. The microprocessor/LED bus is operating correctly. 
The time to execute this test is about 4 seconds. 

D.4 TEST 3 (THREE-BOARD BUS TEST) 
This test checks the module interlocks and communications buses on all 3 
modules provided the test is run under control of the diagnostic terminal. 
This test does not check the personality module bus under the following 
conditions: 
1. The drive is connected to an SDI controller subsystem and this test is 
   run as part of the hardcore test sequence. 

2. The drive is connected to an SDI controller subsystem and this test is 
   run as part of remote diagnosis. 

Errors associated with this test are: 3B, 3C, 3D, 3E, 3F, B3, B4, 50, FO to Fe. 

D.5 TEST 4 (MICROPROCESSOR-ONLY BUS TEST) 
This test checks the bus on the microprocessor board. The SHOW DIAG STAT xxxx 
command may be used to view the test results. The extended status area byte 
9 contains the actual data received in performing this test. Byte 10 contains 
the expected data received in performing this test. 
The error associated with this test is: B3 

D.6 TEST 5 (PERSONALITY/MICROPROCESSOR BUS TEST) 
This test checks the communication bus between the microprocessor and the 
personality modules. It also checks the communication bus on the personality 
module. The error associated with this test is: B4 

D.7 TEST 6 (SERVO/MICROPROCESSOR BUS TEST) 
This test checks the communication bus between the microprocessor and the 
servo modules. Errors associated with this test are: 50, FO to FE. 

D.8 TEST 7 (HEAD SELECF MUX TEST) This test checks the capability of the drive 
to select the r/w heads properly 
Errors associated with this test are: 52, 53, 54. 

D.9 TEST 8 (SECTOR/BYTE COUNTER TEST) 
This test checks the sector and byte counter clocks on the microprocessor 
module to see if they count properly. 
The error associated with this test is: 51 

D.10 TEST 9 (F.E. FRONT PANEL TEST) 
This test checks the ability of the drive to read the front panel switches 
while checking for any bulbs that are burned out. After the test is called in, 
the terminal displays the following: 
   THIS IS THE OPERATOR CONTROL PANEL TEST 
   ENTER A ^C TO EXIT- (ENTER ^C TWICE IF IN LOOP MODE) 
The front panel lights may then be checked by the operator. Open the logic 
access cover on the drive and observe the microprocessor LEDs. As each front 
panel light is pushed, a corresponding LED lights. As the front panel lights 
are turned off, the corresponding LED goes off. This test checks the switch 
decode logic for proper operation. If diagnostic loop mode had been previously 
set by the operator, ^C must be input twice to exit the test and obtain the 
following display: 
    %RA81-COMPLETED TEST:DIAG SUBTEST:09 
    RA8I> 

D. II TEST A (STREAM TEST) 
This test checks for the presence of r/w signals when generated. It also 
checks for the assertion of these signals by the r/w detection circuitry on 
the microprocessor module. 
Errors associated with this test are: 
    50, DO, D6, DA, 65, B8, B9, BA, BB, BC, BD, BE, 25, 30 to 3A and FO to FE. 

D. 12 TEST B (MASTER RAM TIMER TEST) 
This test checks the ability of the RAM timers on the microprocessor module to 
count correctly, 
The error associated with this test is: 57. 

D.13 TEST C (PERSONALITY MODULE LOGIC TEST) 
This test checks the personality module logic. To successfully execute this 
test, loop-back plugs are required in the SDI connectors of the module 
(Figure D-1). 
Errors associated with this test are: 7B, 73, 74, 75, 76, 77, 78, 79, 7A, 
    90, 91, 92, 93, 94, 95, 96, 81, 82, 83, 84. 

D.14 TEST D (PERSONALITY MODULE WRAP TEST) 
This test performs the same testing as Test C with the exception that the 
loop-back function is not checked. This test is also identical to the 
RUN INTE command. This test does not require the loop-back plugs to run. 
NOTE Loop-back plugs left in the drive after running this test cause multiple 
false error indications. 
Errors associated with this test are: 7B, 70, 71, 72, 7C, 7D, 81 

D.15 TEST E (R/W FAULT FORCE TEST) 
This test checks the ability of the drive to detect certain read/write faults. 
Errors associated with this test are: 
    50, DO, D6, DA, AO, A3, A4, A5, A6, A9, 25, 30 to 3A, and FO to FE 

D.16 TEST F (READ ONLY TEST) 
This test checks the ability of the drive to read data from the disk correctly. 
This test uses the dedicated diagnostic read-only cylinder. This cylinder has 
a specific data pattern already written on it. If the data is destroyed, then 
Test 11 may be run to reformat the read-only cylinder. 
Errors associated with this test are: 
    50, DO, D6, DA, 54, 61, 62, 63, 65, 66, 25, 30 to 3A, and FO to FE. 

D.17 TEST 10 (WRITE AND READ TEST) 
This test checks the ability of the drive to write data on the disk and then 
read it back correctly. All read/write heads are used in the execution of this 
test. The test uses the dedicated read/write cylinder of the HDA. Test F must 
be run and sucessfully passed before this test can be executed properly. 
Errors associated with this test are: 
    50, DO, D6, DA, 61, 62, 63, 65, 66, 67, 25, 30 to 3A, and FO to FE. 

--------
Figure D-1 Loop Back Plug Insertion is OMITTED
--------
 
D.18 TEST 11 (READ-ONLY CYLINDER FORMATTER) 
This is a utility program used to reformat the dedicated read-only cylinder of 
the HDA. The program requires a jumper to be inserted from the top of R5 to a 
ground point such as either lead on connector P307. Figure D-2 shows the 
location of R5 and connector P307. 
Errors associated with this test are: 
    50, DO, D6, DA, 61, 62, 63, 65, 66, 68, 25, 30 to 3A, and FO to FE.

---------
Figure D-2 Ground Jumper For Formatter is OMITTED
---------


D.19 TEST 12 (MASTER HARDCORE SEQUENCE TESTS) 
A list of the tests run in this sequence may be found in Appendix B. Note that 
this sequence is not the same as the hardeore sequence run when power is first 
applied. 

D.20 TEST 13 (MASTER READ/WRITE SEQUENCE TESTS) 
This sequence is executed each time the drive is spun up. A list of the tests 
run in this sequence may be found in Appendix B. 

D.21 TEST 14 (SERVO SEQUENCE TESTS) 
This sequence tests the servo logic of the drive. A list of the tests run in 
this sequence may be found in Appendix B. These tests and four others are 
executed automatically as soon as the drive is spun up or down. See spinup 
sequence in Appendix B. 

D.22 TEST 15 (ENTIRE SERVO SEQUENCE TESTS) 
A list of the tests run in this sequence may be found in Appendix B. The drive 
must be spun up in order to run this sequence. 

D.23 TEST 16(ENTIRE DRIVE SEQUENCE, SPUN UP) 
This sequence is run when the user keys in the diagnostic command RUN DIAG 
when the HDA is spun up and the heads are loaded. A list of the tests run 
in this sequence may be found in Appendix B. The time to execute this sequence 
is about 6 minutes, 30 seconds. 

D.24 TEST 17 (ENTIRE DRIVE SEQUENCE, SPUN DOWN) 
This sequence is run when the user keys in the diagnostic command RUN DIAG 
with the drive power on and the RUN/STOP switch not depressed. A list of the 
tests run in this sequence may be found in Appendix B. The time to execute 
this sequence is about 25 seconds. 

D.25 TEST 18 (DRIVE IDLE SEQUENCE TESTS) 
This sequence is run automatically when the drive is in the drive off-line 
mode (both port select buttons are out; i.e., not pushed). A list of the tests 
run in this sequence may be found in Appendix B. The time to execute this 
sequence is about 20 seconds with the drive spun down. With the drive spun up, 
the time is about 30 seconds. 

D.26 TEST 19 (SLAVE ROM TEST) 
This test checks the slave ROM set for consistency and checksum. 
Errors associated with this test are: E2 to E6, 50, FO to FE 

D.27 TEST IA (SLAVE MICROPROCESSOR BUS TEST) 
This test checks the communication bus between the microprocessor and the 
servo modules. 
Errors associated with this test are: 50, FO to FE.

D.28 TEST IB (SERVO PLO TEST) 
This test checks the servo module PLO circuitry. 
Errors associated with this test are: 50, 7B, C6, FO to FE. 

D.29 TEST IC (SERVO SANITY TIMER TEST) 
This test checks the ability of the servo module to generate a trap interrupt 
from the sanity tirner. 
Errors associated with this test are: 50, CE, FO to FE. 

D.30 TEST ID (SERVO DAC TEST) 
This test checks the DAC and the ODAC on the servo module. 
Errors associated with this test are: 50, C8, C9, CA, FO to FE. 

D.31 TEST IE (SERVO POSITIONER LOOP TEST) 
This test checks the ability of the servo to reach fine track status within 
the given time limit. 
Errors associated with this test are: 50, CO, C2, C3, C4, C5, FO to FE. 

D.32 TEST IF (SERVO VELOCITY LOOP TEST) 
This test checks the ability of the servo to maintain the proper read/write 
head velocity during any seek. 
Errors associated with this test are: 50, CB, FO to FE. 

D.33 TEST 20 (SERVO TRACK COUNTER TEST) 
This test checks the ability of the track counters on the servo module to 
count properly. 
Errors associated with this test are: 50, CC, CD, FO to FE.

D.34 TEST 21 (SERVO SLOW SEEK TEST) 
This test checks the ability of the drive to perform a slow seek to the last 
data track and back to track 0. The drive is then requested to perform normal 
1-, 2-, and 4-track seeks. 
Errors associated with this test are: 50, C6, DO, D6, DA, DB, DE, FO to FE. 

D.35 TEST 22 (GUARD BAND DETECT TEST) 
This test checks the ability of the drive to seek into both the inner and outer 
guard bands. The test also verifies that the heads can be loaded while in 
either guard band. 
Errors associated with this test are: 50, DO to DB, FO to FE. 

D.36 Test 23 (INCREMENTAL SEEK, F.E. MODE) 
This test causes the drive to perform incremental seeks. The user specifies 
the starting and ending cylinder addresses. The drive then seeks from the 
starting address to the ending address performing recalibrates in between 
each seek. At the completion of each seek, the starting address is 
incremented by one. 
Errors associated with this test are: 50, DO, D6, DA, DB, DC, FO through FE 

D.37 TEST 24 (SEEK-SEEK, F.E. MODE) 
This test causes the drive to perform seeks to addresses specified by the user. 
Errors associated with this test are: 50, DO, D6, DA, DB, DC, FO through FE. 

D.38 TEST 25 (RANDOM SEEK TEST) 
This test causes the drive to perform random seeks using the random seek table 
to specify the cylinder addresses. 
Errors associated with this test are: 50, DO, D6, DA, DB, DD, FO through FE. 

D.39 TEST 26 (SEEK-SEEK, DEFAULT MODE) 
This test causes the drive to perform seeks between the first and last data 
cylinders. Errors associated with this test are: 
       50, DO, D6, DA, DB, FO through FE. 

D.40 TEST 27 (INCREMENTAL SEEK, DEFAULT MODE) 
This test causes the drive to perform an incremental seek between the first 
and last data cylinders. 
Errors associated with this test are: 50, DO, D6, DA, DB, FO through FE. 

D.41 TEST 28 (SERVO OUTER GUARD BAND SEEK) 
This test checks the ability of the drive to seek into and detect the outer 
guard band. Errors associated with this test are: 
       50, DO, D4, D6, DA, DB, DD, FO through FE. 

D.42 TEST 29 (SERVO INNER GUARD BAND VERIFY) 
This test checks the spindle status and the ability of the drive to load the 
heads. Errors associated with this test are: 50, DO, D6, DA, FO through FE. 

D.43 TEST 2A (SERVO RECALIBRATION) 
This test causes the drive to perform a recalibration, detenting the heads on 
cylinder 0. 
Errors associated with this test are: 50, DO, D6, DA, DB, DD, FO through FE. 

   


APPENDIX E SYSTEM FAULT CODES


Table E-1 lists th'e'RA81 drive errors and fault display codes. 
NOTE Loop-back plugs left in the drive following execution of 
Diagnostic Test C cause multiple false error codes to be displayed. 

Table E-1 Drive Error Display Codes 
Error Code      Name 
0l       Spindle motor speed transducer timeout 
02       Spindle speed of 1000 r/min not reached in 6 seconds during spinup 
03       Spindle not accelerating during spinup 
04       Spindle speed of 3420 r/min not reached in 40 seconds during spinup 
05       Startup being inhibited by power sequencing grant not present or 
         start in progress (SIP) present (this could be legitimate status) 
06       Microcode fault 
07       Level two message frame sequencing error 
08       Level two message checksum error 
09       SDI message framing error 
OA       Invalid operation code parity for a level I or 2 message 
OB       Invalid operation code for a level I or 2 message 
0C       Invalid command length for a level 2 message E-1 
OD       Status error byte non-zero while attempting to execute a command 
OE       Group select code non-zero while attempting to execute a command 
OF       Write protect switch is in the PROTECT position while attempting 
         to write enable the drive 
10       Invalid error code sent by slave 
13       Fine track not reached during detent mode 
15       Too much time taken to execute a seek or recal command 
16       Guard band detected while performing a seek command 
17       Seek logic difference counter decremented past 0 before expected 
         cylinder was reached 
1A       Seek command contains an invalid cylinder address 
1B       Velocity calibration detected too many bad seeks 
1C       Unsuccessful recalibrate command detected during a velocity 
         calibration 
1D       Drive seeks are more than 10% too fast 
1E       Drive seeks are more than 15% too slow 
1F       A sector pulse is detected during the execution of a read or write 
         of a sector 
20       A parity is error detected on the controller real-time state line 
21       Two or more pulses of the same polarity are detected on the 
         controller real-time state line (control pulse error) 
22       Two or more pulses of the same polarity are detected on the 
         controller write command data line (data pulse error) 
23       Spindle motor interlock broken (belt tension lever is released) 
25       Servo error (SVOCHK) detected (off track during detent mode) 
26       Spindle speed is detected as being less than 3420 r/min (3600-5%) 
27       HDA temperature too high 
28       Servo module temperature too high 
29       Invalid error recovery level specified 
2A       Invalid subunit specified 
2B       Invalid region specified in a diagnose command 
2C       Seek or recal command attempted while the spindle is not spinning 
2D       Invalid command timeout value given 
2E       Controller flags are detected prohibiting drive spinup 
2F       RUN/STOP switch is in the stop position while attempting a run command 
30       Write current is turned on without write gate being asserted 
31       A read command is attempted with write gate asserted 
32       A read or write command is attempted while the drive is faulted 
33       A burst error is detected while writing 
34       Read data separator/encoder error 
35       Write unsafe error detected while attempting a write command 
36       Short circuit detected in head winding 
37       No write current detected with write gate asserted 
38       A read command is attempted with multiple heads selected 
39       A write command is attempted while the positioner is off track 
         (not detented)
3A       A write command is attempted while the drive is write protected 
3B       Servo/HDA interlock broken 
3C       Servo interlock broken 
3D       Read/Write interlock broken 
3E       Control panel interlock broken 
3F       Personality module interlock broken 
40       Invalid R/W region specified 
41       SDI controller response timed out 
42       Drive not in an on-line state while attempting a seek command 
43       R/W READY not set while attempting a real-time command 
44       Format enable not set while attempting a format command 
45       Real-time command contains an invalid head (track) address 
46       R/W safety interrupt occurred with no cause bits set 
47       Disconnect command contains an incorrect TT bit 
48       Invalid write memory offset or byte count 
49       Invalid command found while in topology mode 
4A       Drive is disabled by DD bit 
4B       Index pulse error 
4D       Bad embedded servo data found during a write command 
50       Slave diagnostic timeout NOTE This error could be the result of 
         the positioner lock lever in the lock position. 
51       The sector/byte failed to count properly 
52       Group 0 cannot be selected 
53       Group I cannot be selected
54       R/W head select error-while executing the head select multiplexer test 
57       Master RAM timer faulty 
60       R/W head select error while executing read/write test 
61       R/W data setup error (diagnostic write data register not equal to 
         diagnostic read data reg.) 
62       The data from 3 or more heads is bad while executing the read only test 
63       The data from I or 2 heads is bad while executing the read only test 
65       Read/Write test sector could not be found within two revolutions of 
         the disk. 
66       Read failure caused by servo being off-track 
67       Write test cannot be executed because Test F was not run or failed 
68       Read-only cylinder cannot be reformatted without jumper 
69       Read/Write diagnostic comparison circuitry never detects an error 
6F       Diagnostic write attempted while write protected 
70       Command available timeout error during execution of PCB wrap test 
71       SDI INIT always asserted 
72       No control clock or framing error occurred during execution of PCB 
         wrap test 
73       Microprocessor and PCB board data bus communication error 
74       Initial personality board status incorrect for offline condition 
75       Failure in control clock error detect circuit 
76       Failure in data clock error detect circuit 
77       Port A select latch failed 
78       Port A data transmitter/receiver error 
79       Port A control line transmitter/receiver error 
7A       Port B select latch failure 
7B       Spindle motor spinning while attempting PCB test 
7C       Received error in frame code during PCB wrap test 
7D       Received error in data byte during PCB wrap test 
80       Consistency fault detected in master ROM 
81       Command available did not reset after reading data 
82       Frame code did not reset after reading data 
83       Cannot receive SDI INIT from Port B 
84       INIT bit not clear following INIT 
85       Master RAM 0 failed RAM test 
86       Master RAM I failed RAM test 
87       Checksum error detected in master ROM 0 
8F       Checksum error detected in master ROM 1 
90       Port B data transmitter/receiver error 
91       Port B control line transmitter/receiver error 
92       Port A wraparound error 
93       Response scrializer error 
94       Loop-around frame not received properly 
95       Loop-around frame was not decoded properly 
96       Loop-around frame data byte was not received properly 
97       Cheeksum error detected in master ROM 2 
9F       Checksum error detected in master ROM 3 
AO       Unable to clear faults at R/W safety register 
Al       Unable to force head short error while writing 
A2       Unable to force multiple head select error while reading 
A3       Unable to force read gate and write gate active at the same time 
A4       Unable to force write current without write gate 
A5       Unable to force write gate without write current 
A6       Unable to force a miscompare of the data from the write compensation 
         logic and the read encoder logic 
A7       Checksum error detected in master ROM 4 
A9       Servo fault caused a R/W forced fault 
AA       Diagnostic firmware OK prompt code 
AF       Checksum error detected in master ROM 5 
BO       Test will not run due to a drive fault 
B3       Bus test error in microprocessor module 
B4       Bus test error in personality module 
B6       UART transmitter/receiver error 
B8       Stream test write clock not active 
B9       Stream read clock not active 
BA       Stream buffered servo clock not active 
BB       Stream ECL write data not present 
BC       Stream encoded write data not present 
BD       Stream decoded read data not present 
BE       Stream ECL read data not present 
BF       Unable to reset stream bit 
CO       Fine track timer error  
C1       Fine track status not true 
C2       Fine track status not false 
C3       Fine track over-range error 
C4       Fine track under-range error 
C5       Wrong fine track channel detected 
C6       PLO error 
C8       ADC/DAC reference voltage not within range 
C9       ADC/DAC bit error 
CA       ADC/ODAC bit error 
CB       Servo velocity test acceleration status error 
CC       Seek difference counter did not load correctly 
CD       Seek difference counter error or the old Gray code bits are wrong 
CE       Servo sanity tests timer error 
DO       Load attempt failed 
D1       Outer guard band detected following a head load operation 
D2       Inner guard band detected following a head load operation 
D3       Seek into the outer guard band failed 
D4       Outer guard band not detected following a seek into the outer 
         guard band 
D5       Load from outer guard band failed 
D6       Spindle not up to speed 
D7       Seek into inner guard band failed 
D8       Inner guard band not detected following a seek into the inner 
         guard band 
D9       Load from inner guard band failed 
DA       Spindle not spinning 
DB       Diagnostic seek failed 
DC       Incorrect parameters entered during execution of drive-resident 
         diagnostics 
DD       Recalibrate error 
DE       Low velocity seek error 
DF       Spinup failed 
EO       Random seek error 
El       Integrator error 
E2       Slave ROM consistency error 
E3       Checksum error on slave ROM 0 
E4       Checksum error on slave ROM I 
E5       Checksum error on slave ROM 2 
E6       Checksum error on slave ROM 3 
E7       Test execution code 
E8       Error in slave RAM 0 
E9       Error in slave RAM I 
EE       Incorrect test parameter entered 
FO       Slave uncommanded spindown 
Fl       Slave load timeout 
F2       Slave sent an unexpected message 
F3       Slave received a bad command packet 
F4       Slave operation code parity error 
F5       Slave received an invalid operation code 
F6       Master received a bad status packet from slave 
F7       Slave recalibrate timeout NOTE This error could be the result of the 
         positioner lock lever in the lock position. 
F8       Slave seek timeout 
F9       Slave offset timeout 
FA       Slave spinup timeout 
FB       Slave spindown timeout 
FC       Slave send status timeout 
FD       Slave initialization timeout 
FE       Slave speed check timeout

APPENDIX F FRONT PANNEL FAULT IDENTIFICATION

This appendix is used to identify faults called out by the front pannel
indicator lights.  Table F-1 shows the status of the front pannel lights
for each type of error reported.

Table F-1 Drive Front-Panel Fault Identification Codes 
 Fault Condition     RUN/    FAULT    RDY    WRITE   A     B    Status Byte 
                     STOP                    PROT               15 Hex Code 

Index error          on       on                                    11

Master/Slave
error                         on             on                     12

Servo diagnostic
test error           on       on             on                     13

Microprocessor
fault                         on                     on             14

Drive disabled
by DD bit            on       on                     on             15

Servo coarse
positioning                   on             on      on             16
error

Diagnostic idle
loop test error      on       on             on      on             17

Spin error                    on                            on      18

Write and bad        
embedded data        on       on                            on      19

Servo fine
positioning                   on             on             on      1A
error

R/W diagnostic 
test error           on       on             on             on      1B 

SDI error                     on                     on     on      IC 

Write enable 
and write protect    on       on                     on     on      1D 
asserted error 

Spindle motor 
interlock error               on             on      on     on      1E 

Servo or HDA 
overtemp error                on       on                           30 

Servo/microprocessor 
interlock error               on       on    on                     32 

R/W command error             on       on            on             34 
Control panel/ 
microprocessor 
interlock error               on       on    on      on             36 

R/W unsafe error              on       on                   on      38 

Read/write 
microprocessor                on       on    on             on      3A 
interlock error 

Servo/HDA 
interlock error               on       on            on     on      3C 

Personality/ 
microprocessor                on       on    on      on     on      3E 
interlock error 

Microprocessor 
hardcore test        on       on       on    on      on     on      3F 
error 

DC low               on                on    on      on     on      *

*NOTE The DC Low condition locks up the drive logic and therefore cannot 
have a hexadecimal code represented by the host system diagnostics. 

APPENDIX G ERROR CODE TROUBLESHOOTING TABLE


Table G-1 Drive Error Code/FRU Reference List 

Table G-1 correlates the error codes that are displayed by the subsystem 
diagnostics or the field service diagnostic terminal to an FRU reference code. 
Appendix H provides names and part numbers for FRUS. Note that more than one 
error code can result in the same FRU reference. 


Error 
Code   FRU Probable Cause
01   Mtr/Brk assembly, belt, servo module, power supply,
02   speed transducer
03 
04  
05   The power sequencing signals are inhibiting the startup of the drive. 
     Probably caused by the preceding drive not being up to speed. Check to 
     see if the drive can spin up with the power sequencing jumper moved to 
     this drive. If drive spins up then problem is with the preceding drive. 
     Replace personality module, microprocessor module, and the cables between 
     the two drives. If the drive did not spin up, then the problem is with 
     the drive that displayed the error. Check modules and cables as outlined 
     above. 

06   Microprocessor module, servo module
07   Personality module, SDI cables, controller
08 
09 
OA 
OB 
0C  
OD   SDI cables, controller
OE 
OF  
10   Servo module, microprocessor module
13   Servo module, R/W module, HDA 
15   Servo module, HDA 
16 
17 
18   Servo module, microprocessor module 
1A   SDI cables, controller 
1B   Servo module, R/W module, HDA 
1C 
1D   Servo module, HDA 
1E 
1F   Microprocessor module, SDI cables, controller 
20   Personality module, SDI cables, controller 
21 
22 
23   Check cables or motor belt interlock           
25   Servo module, microprocesor module, motor/brake assembly, belt, 
     power supply, HDA 
26   Motor/Brake assembly, belt, servo module, power supply, speed transducer 
27   Check fans, ambient room temperature and temperature sensor for proper 
     operation. Check proper seating of cable from R/W to microprocessor 
     module. If OK, then replace the R/W module, microprocessor module, cables,
     HDA. 
28   Check fans and ambient room temperature. If OK, then replace servo module,
     microprocessor module, cables between microprocessor and servo module. 
29   SDI cables, controller 
2A 
2B 
2C 
2D 
2E 
2F 
30   Microprocessor module, R/W module, personality module, HDA 
31   Microprocessor module, personality module, SDI
32   cables, controller
33 
34   Microprocessor module, R/W module, personality module, HDA
35 
36   R/W module, microprocessor module, HDA
37 
38   
39   Servo module, R/W module, HDA 
3A   Microprocessor module, SDI cables, controller
3B   Check servo/HDA cable, read-write/HDA cable
3C   Check servo/microprocessor cable
3D   Check read-write/microprocessor cable
3E   Check control panel/microprocessor cable
3F   Check personality/microprocessor cable
40   SDI cables, controller
41  
42   SDI cables, controller
43 
44 
45    
46   Microprocessor module, power supply
47   SDI cables, controller
48 
49 
4A 
4B   Servo module, microprocessor module, motor/brake 
     assembly, belt, power supply, HDA
4D   R/W module, servo module, HDA, microprocessor module 
50   Ensure that positioner motor lock is in the unlock position. If OK, 
     then replace servo module, microprocessor module 
51   Microprocessor module 
52 
53 
54 
57 
60 
61   Personality module, microprocessor module 
62   R/W module, microprocessor module, personality module, HDA 
63   R/W module, microprocessor module, HDA 
65   Microprocessor module, servo module 
66   Servo module, R/W module, HDA 
67   Test 10 (write and read test) was attempted before a successful 
     completion of test OF. 
68   Install the juniper to run test I I successfully. 
69   Microprocessor module, R/W module, reformat the read-only cylinders 
     using Test II. 
6F   Remove write protect status from drive. If OK, then replace 
     microprocessor module, control panel module. 
70   Personality module, microprocessor module 
71 
72 
73 
74 
75 
76 
77 
78   Insert SDI loop-back plugs, personality module 
79   Personality module, microprocessor module 
7A 
7B   Spin down the disk 
7C   Personality module, microprocessor module 
7D 
80   Microprocessor module 
81   Personalty module, microprocessor module 
82 
83 
84 
85   Microprocessor module 
86 
87 
8B   Microprocessor module, personality module, SD controller 
8F   Microprocessor module 
90   Insert SDI loop-back plugs, personality module 
91   Personality module, microprocessor module 
92 
93 
94 
95 
96 
97   Microprocessor module 
9F 
AO 
Al   Microprocessor module, R/W module 
A2 
A3   Microprocessor module 
A4   Microprocessor module, R/W module 
A5   Microprocessor module 
A6 
A7 
A9   Servo module, R/W module, HDA 
AF   Microprocessor module 
AB   Servo module, HDA 
BO   A drive fault is inhibiting the running of a test. Check microprocessor 
     LEDs for a specific drive fault. 
B3   Microprocessor module 
B4   Personality module, microprocessor module 
B6   Ensure the diagnostic terminal cable is not connected. Check the 24 volt 
     supply to the microprocessor module. If 24 volts is missing then check 
     cable to module then replace power supply. If OK, then replace the 
     microprocessor module 
B7   R/W module, microprocessor module, personality module, HDA 
B8   Personality module, microprocessor module 
B9   Microprocessor module, servo module 
BA   Servo module, microprocessor module 
BB   Microprocessor module 
BC 
BD   R/W module, microprocessor module, HDA 
BE 
BF   Microprocessor module 
C0   Servo module 
Cl 
C2 
C3 
C4 
C5 
C6 
C8 
C9 
CA 
CB 
CC 
CD 
CE 
DO   Servo module, R/W module, HDA 
D1 
D2 
D3   Servo module, HDA 
D4   Servo module, R/W module, HDA 
D5   Servo module, HDA 
D6   Motor/Brake assembly, belt, servo module, power supply, speed transducer 
D7   Servo module, R/W module, HDA 
D8   Servo module, HDA 
D9   Servo module, R/W module, HDA 
DA   Spin up disk 
DB   Servo module, R/W module, HDA 
DC   Reenter parameters 
DD   Servo module, R/W module, HDA 
DE 
DF   Motor/Brake assembly, belt, servo module, power supply, speed transducer 
EO   Servo module, R/W module, HDA 
El   Servo module 
E2 
E3 
E4 
E5 
E6 
E8   Servo module 
E9 
EE   Illegal test parameter 
F0   Motor/Brake assembly,belt,servo module, power supply, speed transducer
F1   Servo module, R/W module, HDA
F2   Servo module, microprocessor module
F3   Microprocessor module, servo module
F4
F5
F6   Servo module, microprocessor module
F7   Servo module, R/W module, HDA
F8
F9   Servo module, microprocessor module
FA
FB
FC
FD
FE