Service manual

6 143
Digital Control Troubleshooting
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6. Digital Control Troubleshooting
2. Press all of the front panel keys. The abbreviated key name should be displayed when a
key is pressed. When you rotate the RPG knob, the RPG tuned direction (CW or CCW)
and its response speed (SLOW, MID, FAST) should be displayed. You can check every
key on the A30 Keyboard except for
[Preset]. (If you want to exit this test, press
[Preset].)
• If one or more keys seems to be defective, replace the A30 front keyboard.
• If all keys seem to be good, the A30 front keyboard is verified. Continue with the
next Check the A53 FDD.
6. Check the A53 FDD
The A53 FDD (Flexible Disk Drive) can be checked using the external test 18: FLOPPY
DISK DRIVE.
1. Press [Preset], [System], DIAGNOSTIC TEST, [1], [8], [x1], RUN TEST to run the
external test 18.
2. As the analyzer instructs, insert a flexible disk into FDD. Use a formatted but blank
flexible disk, otherwise the data on the disk will be overwritten by this test. Then press
CONT.
3. Check the test result, PASS or FAIL, that is displayed at the end of the test.
• If this test fails, replace the A53 FDD.
7. Check the A32 I-BASIC Interface and the mini DIN Keyboard
The mini DIN external keyboard is connected to the A32 I-BASIC I/O connector, and is
used to develop programs.
If the external keyboard of the I-Basic is not working, perform the following procedure to
verify the keyboard.
Press [Preset], [System], DIAGNOSTIC TEST, [1], [x1], RUN TEST to run the internal test
1: A1 CPU.
• If the internal test 1 passes, the HP driver circuit on the A1 CPU is probably working.
Inspect cables between the external keyboard and the A1 CPU through the A32
I-BASIC interface. If the cable is good, replace the external keyboard.
• If the internal test 1 fails, replace the A1 CPU.
8. Check the 24 BIT I/O PORT
Perform the following procedure to verify the 24 BIT I/O PORT using the I/O Port Test Kit
(PN 87510-65002). The 24 BIT I/O PORT is connected to the I/O control on A51 board
through the A20 motherboard.
1. Turn the analyzer off.
2. Connect the I/O Port Test Kit to the 24 BIT I/O PORT on the analyzer’s rear panel as
shown in
Figure 6-7.