Digital Equipment VAXstation I Service Manual page 83

MAINTBNANCE
Table 3·11: Troubleshooting Flow
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STEP
I
PROCEDURE/DECISION
I
BRANCH
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START Turn system power ON.
Does system bootstrap?
N •>
l
Is the system operating reliably? N •> 20
DONE
l Is DC OK LED ON?
"MICROVERIFY STARTED" displayed on monitor?
Garbled or no monitor display?
Error number in Microverify LED display?
Error message dispalyed on monitor?
2
Is AC power switch lighted?
Both fans turning?
Turn power OFF.
Remove all modules except CPU.
Turn power ON.
Is DC OK LED ON?
a) Turn power OFF.
b) Re-install one module in backplane.
c) Turn power ON.
d) Is DC OK LED ON?
Repeat a), b), c) until d) =NO
3 Check: AC wall receptacle
AC power cord
AC circuit breaker
Power-on switch
AC power switch
4 Possibly power supply and/or fan.
5
6
Replace fan; or
Replace H7864 power supply.
Return to START
Replace H7864 power supply.
Return to START
Replace failed module.
Is DC OK LED ON'?
Return to START
3-29
N •>
2
N •>
8
y
=> 10
y
•> 14
y
=> 19
N
->
20
N ->
3
N
•> 4
N
•>
5
N
•> 6
N =, 7