Repair manual

3-17
TROUBLESHOOTING
CRT Filament Not Lit
Turn Off Power
Unplug CRT Socket
Use VOM to Check Continuity
Between Pins3 & 4 of CRT
Continuity?
Yes No
Plug In CRT Socket and
Turn On Power
Replace CRT Assembly
(Depot Repair Only)
Use VOM to Check Voltage
Across E2 and E3
12 vdc + 0.1 vdc?
Yes No
CRT Socket Defective
12 vdc at P9-1
Yes No Check Power Supply Voltages
on Connectors J3, J4, J5
Pin 1 -12v
Pin2 +12v
Pin3 (GRND)
Pin4 +5v (vcc)
Yes No
Check Power Supply
Fuse F1, OK?
Check Logic Board Test Points:
TP12 (GRND)
TP13 +5vDC
TP14 +12vDC
TP15 -12v DC
Yes No
Yes No
Replace
Power Supply
Replace F1
Check Wiring
& Connectors
Diagnostics OK?
Yes No
Replace Logic Board
Check All Wiring
Chart 7
Replace Monitor
Board Assembly
Check All Wiring &
Correct Defects