Gasboy 1000 Series FMS Diagnostic Manual - Manual (Page 118)

Troubleshooting
03/07/03 6-33 33
Printer can't enter self-test, printer can't exit self-test.
Can't Enter Self-Test
Possible Cause
Checks Corrective Action
Printer is not online. Examine online LED on Printer
Status PCB. If online LED is off, push
online switch on Printer Status
PCB to place printer online.
Defective self-test switch. Using a DC voltmeter,
measure between DC ground
and P2 pin 4 of the Printer
Status PCB. +12VDC is
measured when self-test
should be off; 0VDC is
measured when self-test
should be on. Turn self-test
switch from off to on. Does
voltage change? Replace Printer Status PCB if
voltage does not change when
switch position is changed.
Defective switch sense IC on
Auxiliary Communications Port
PCB or defective MPU PCB. Using a DC voltmeter,
measure between DC ground
and U12 pin 4 of the Auxiliary
Communications Port PCB.
+5VDC should be measured
when self-test should be off;
0VDC should be measured
when self-test should be on. Replace the Auxiliary
Communications Port PCB if
+5VDC is measured when
self-test should be on.
Replace the MPU PCB if
0VDC is measured on U12,
pin 4, of the Auxiliary
Communications Port PCB
when self-test should be on
but self-test is not initiated.