Table of Contents
Advertisement
4-18
Troubleshooting
Troubleshooting
Troubleshooting information for the various circuits is summarized below. See Principles of
operation for circuit theory.
Display board checks
If the front panel DISP test indicates that there is a problem on the display board, use Table
4-2.
Table 4-2
Display board checks
Step
Item/component
1
Front panel DISP test.
2
P1005, PIN 5
3
P1005, PIN 9
4
U401, PIN 1
5
U401, PIN43
6
U401, PIN 32
7
U401, PIN 33
Required condition
Verify that all segments operate.
+5V ±5%
+37V ±5%
Goes low briefly on power up,
then goes high.
4MHz square wave.
Pulse train every 1msec.
Brief pulse train when front
panel key is pressed.
Remarks
Use front panel display test.
Digital +5V supply.
Display +37V supply.
Microcontroller RESET.
Controller 4MHz clock.
Control from main processor.
Key down data sent to main
processor.
Advertisement
Table of Contents
Troubleshooting
