Diagnostic Test Program Execution Check - Toshiba T1950 User Manual

Procedure 4

Diagnostic Test Program Execution Check

Execute the following tests from the Diagnostic Test Menu. Refer to Chapter 3, Tests and
Diagnostics, for more information on how to perform these tests.
1. System Test
2. Memory Test
3. Printer Test
4. ASYNC Test
If an error is detected during these tests, go to Procedure 5.
Procedure 5 System Board Replacement Check
The upper (FATSU*) or lower (FATSL*) system board may be damaged. (Note that the
power supply is mounted on the FATSL*.) Refer to the T1900/T1900C parts catalog for a
breakdown of the computer's system boards.
Disassemble the T1900/T1900C following the steps described in Chapter 4, Replacement
Procedures, then perform the following checks.
NOTE: To determine whether to first replace the FATSU* or the FATSL* during the
troubleshooting procedures:
1. Check the error status on the printer port LED and locate the status in Table 2-2 or 2-
3.
2. Compare the error status with the tables in Appendix B.
If the error is related to an IC or connector listed in Table B-1 or B-2,
replace the FATSU* (upper system board) first.
If the error is related to an IC or connector listed in Table B-3 or B-4,
replace the FATSL* (lower system board) first.
As an example, if the error status indicates a keyboard (KBC) problem, replace the
FATSU* since the keyboard controller (IC15) is located on the upper system board,
then continue with the troubleshooting procedures. However, if the error indicates a
PCMCIA problem, replace the FATSL* first since the PCMCIA Gate Array (IC203) is
located on the lower system board.
Check 1 Replace the upper or lower system board.
Check 2 If normal operation is restored after replacing the upper (or lower) system board,
the original board is probably defective.
Check 3 If normal operation is not restored, replace the original system board, then swap
out the remaining system board with a new one.
Check 4 If normal operation is still not restored, either both system boards or another FRU
is probably defective. The defective unit must be isolated by performing the
T1900/T1900C Diagnostics Program.
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