CHAPTER 4 TA78 TROUBLESHOOTING AIDS
4.2 FAULT CONTROL AND ERROR CODES
The FAULT indicator lights to show that a potentially fatal error has been detected in the formatter. When FAULT stays l i t , perform the following procedure.
1. Press and release the FAULT button. All three TS78 control panel i nd ica tor s l i g h t i n a lamp test. These indicators stay on for as long as you press the FAULT button, or for at least one second. After you release the FAULT button, the A, B, and FAULT indicators light to display a binary error code. The code, defined in Table 4-1, identi f ies one of six areas in the format ter tha t may have caused the error.
2. Record the displayed fault number.
3. Press the FAULT button again for about one second and then release i t . The format ter then tr ies to clear the error. All three i nd ica tors 1 igh t as long as you press the FAULT button or until the clear attempt is finished.
If the error is cleared, the FAULT indicator turns off and PORT SELECT A and PORT SELECT B return to their normal meaning. If the error remains, FAULT stays on and PORT SELECT A and PORT SELECT B are off.
4-1
OBTAIN FAULT NUMBER + ASSOCIATED
MICRODIAGNOSTIC PAR 4.2 CHAIN. ATTEMPT
TO CLEAR FAULT.
CONNECT EXT·
ERNAL TERMINAL TO TA78 ASCII MAINTENANCE PORT
RUN CHAIN ASSOCIATED WITH FAULT
REPLACE PRIMARY FRU AND RERWN CHAIN.
IF ERROR STILL PRESENT, REPLACE SECONDARY FRU AND RERUN CHAIN AGAIN.
FIG 2-25
PAR 4.3.1
PAR 4.3.2
A
YES
CONNECT EXTERNAL TERMINAL TO HSC ASCII PORT OR USE PREVIOUSLY INSTALLED EXTERNAL TERMINAL
REPLACE PRIMARY FRU AND RERUN CHAIN O.
IF ERROR STILL PRESENT,REPLACE SECONDARY FRU AND RERUN CHAIN 0 AGAIN
NO
PAR. 2.5.3
PAR. 4.3.2
SHR0106B-84
Figure 4-1 TA78 Troubleshooting Flowchart (Sheet 1 of 2)
CONNECT EXTERNAL TERMINAL TO HSC ASCII PORT OR USE PREVIOUSLY INSTALLED EXTERNAL TERMINAL
PAR 4.6 NOTES:
USE OTHE.R
CD
TABLE 6·2
&
PAR 3.3
STANDARt> TU78 CH 5 TROUBLESHOOTING PROCEDURES
RUNNING ILTAPETOTEST FORMATTER RUNS TESTS IN CHAIN 0
USE ILTAPE AND ILEXER AS DISCUSSED IN PARAGRAPH 2.5.3 TO VERIFY ANY FIXES EXCEPT FORMATTER ERROR FIXES
IF PROBLEM STILL EXISTS WHEN END IS REACHED, CALL SUPPORT
TEST FORMATTER SWITCHES WITH BUTTONS AND LIGHTS TEST
SHR0107B·B4
PAR 4.7.1.1
PAR 4.3.3
TABLE 6·2
PAR 4.7.2
Figure 4-1 TA78 Troubleshooting Flowchart (Sheet 2 of 2)
4-3
4. If the FAULT indicator stays on, run the associated microdiagnostic chain specified in Table 4-1 for the recorded fault number. (Refer to Paragraph 4.3.1 for instructions on running microdiagnostics.)
NOTES
time, the microcomputer runs the minimum integrity and power-up d i a 9 nos tic s. Wh e n t h e i n d i cat 0 r s turn off, repeat step 1. However, if the three indicators stay on, the microcomputer is probably bad.
Replace the M8972 and repeat step 1.
If the error code does not appear after releasing FAULT [i.e.;
indicator(s) not flashing], the microcomputer is probably bad.
Replace the M8972 and repeat step 1.
4.3 MICRODIAGNOSTICS
The TS78 contains 56 microdiagnostic test routines which are divided into two categories: in-line and off-line. The 16 in-line tests reside in read-only-memory (ROM) on the M8972 module. The microprocessor (8085) schedules sequential running of in-line tests while the formatter is not on-line to verify basic operation. In most cases, the 8085 only activates self-test programs in control ROMs on various modules.
The off-line microdiagnostics thoroughly test the formatter and any tape transport interface (MIA) module connected to the formatter. However, these tests cannot be run under normal operating conditions. Thirty-eight off-line tests reside in ROM on the M8973 module. On request, the 8085 moves a microdiagnostic from M8973 ROM to the M8972 random access memory (RAM). The 8085 then runs a checksum test on the transferred microdiagnostic and ex e cut e s t hem i c rod i a g nos tic. Th e r em a i n i n g two 0 f f ~ 1 i n e t est s reside in M8972 ROM and are simply executed by the 8085 on request. These two tests present sample reports of passing and failing microdiagnostics. Note that three off-line tests in M8973 ROM are STl loopback tests that require installation of a loopback connector(s) •
Anyone of the 56 microdiagnostics can be run individually through the ASCII port. Table 4-2 lists the in-line microdiagnostics and the test numbers used to access them. Table 4-3 lists the off-line microdiagnostics along with test numbers.
4-5
Table 4-2 In-Line Microdiagnostics
Test Test
Number Name Description
1 I NWMC write microcontroller self-test 2 INXMC Translator self-test
3 INRPM Read path controller self-test 4 INRCH0 Read channel 0 self-test
5 INRCHl Read channel 1 sel f-test 6 INRCH2 Read channel 2 self-test 7 INRCH3 Read channel 3 sel f-tes t 8 INRCH4 Read channel 4 self-test
9 INRCH5 Read channel 5 self-test A INRCH6 Read channel 6 self-test
B INRCH7 Read channel 7 self-test C INRCHP Read channel P self-test
D INECC E'rror correcting code controller self-test E INMEM Microcomputer RAM memory test
F INCHK0 Micl:ocomputer ROM checksum test 10 INCHKl Extended memory ROM checksum test
Table 4-3 Off-line Microdiagnostics
Test Test
Number Name
20 PASS
21 FAIL
100 WMCITD
110 WMC2TD
120 WMC3TD
130 WMC4TD
140 WMC5TD
150 TUP1TD
160 MTAITD
Description
Prints report for successful test pass Prints error report for test failure Write microcontroller (WMC) microbus interface test
WMC data format/skip count test WMC write data byte assembly test
WMC write GCR check character generation test
WMC write PE ECC character generation test (note 1)
TU port boards test
MIA board(s) test; includes loop command to status, loop microcomputer to AMTIE lines and loop microcomputer to RD lines for MIA board in any transport present
Table 4-3 Off-line Microdiagnostics (Cont)
Test Test
Number Name Description 170
MIA loop threshold/command function test MIA tachometer line continuity test
Translator (XMC) track enable test XMC PE preamble/postamble test
XMC GCR preamble/postamble test; with 1 channel fifos statically, checks read
channel data handling from a~l 4 TU ports, and tests RMC velocity-check circuit
Read path and channel test; checks ability
Table 4-3 Off-line Microdiagnostics (Cont)
ECC module single-track error correction test; with no TIE pointers and correct TIE pointers
ECC module single-track error correction test; with incorrect TIE pointers
ECC module test; checks double-track error correction with correct TIE pointers and checks no error correction with good data and 3 hard pointers
ECC module test; checks double-track
correction with 2 hard pointers and 7 soft pointers and checks error discrimination to correct errors in outer tracks (1 and 9) with 9 soft pointers
Cyclic redundancy checker (CRC) module test (note 2)
Protocol microcontroller (PM) data path test:
PM ROM controller/microbus interface test PM flag EDC and timer test
Table 4-3 Off-line Microdiagnostics (Cont)
Test Test
Number Name Description
330 STIlTD STI interface error detection and reset test
350 STI2TD STI interface port A loopback test 360 STI3TD ST I interface port B loopback test
370 STI4TD STI interface port A and B loopback test NOTES
1. Run time for this test is between 30 and 60 seconds per pass.
2. Run time for this test is over 60 seconds per pass.
The TS78 al so conta ins 10 microd iagnost ic cha i ns tha t res ide in M8972 ROM. In most cases, these chains specify sequences of related microdiagnostics. You request chains through the ASCII port like the other tests. Table 4-4 defines the chains and the numbers used to access them. Requesting a chain causes the 8085 to run the associated microdiagnostic(s) listed in Table 4-4.
Requesting chain 0 (full set) via the ASCII port runs all the microdiagnostics except the M8970 tests, M897l tests, and sample report tests (PASS and FAIL). Running the ILTAPE subsystem diagnostic to test the formatter also runs the tests in chain 0.
Chains 401 407 test various parts of the formatter defined by the fault numbers in Table 4-1. After a clear attempt with the FAULT button, the 8085 runs the proper chain to determine if the error is still there. If the error still exists, run the proper chain through the ASCII port to determine the field replacement uni t (FRU).
Ch a i n 4 09 (m i n i m urn i n t e g r i t y) qui c k 1 y t est s i f the for mat t e r i s able to communicate via the STI bus. Running this chain and the appropr ia te STI loopback prov ides a more complete test of STI communication. Powering up the TA78 or pressing the MASTER RESET button causes the 8085 to run chains 408 and 409.
4-9
Table 4-4 Microdiagnostic Chains Chain Chain
Number Name