ViewSonic PerfectFlat E90fB-4 Service Manual page 23

6-3. NO BLANKING
CHECK THE RELATIVE
CIRCUIT OF BLANKING
OK
CHECK R821 ON VIDEO PCB,
CHECK G1 RELATIVE CIRCUIT
FBT PIN 5 ON MAIN PCB
6-4. HOR./OSC/DEF/HV CIRCUIT FAULT
6-4-1. NO RASTER (DISCONNECT WITH SIGNAL CABLE)
CHECK IC101 PIN 16 ABOUT 5 VDC
OK
CHECK IC101 PIN20 WAVE FORM
ABOUT 3Vpp
OK
CHECK THE COLLECTOR VOLTAGE
OF Q402 ABOUT 14Vpp
OK
CHECK THE COLLECTOR VOLTAGE
OF Q403 ABOUT 1200Vpp AT FH:31KHz
ViewSonic Corporation
NG
NG
NG
NG
NG
CHECK THE RELATIVE CIRCUIT
OF FBT
CHECK IC101 PIN 5 RELATIVE CIRCUIT
CHECK IC101 PIN20
RELATIVE CIRCUIT
CHECK Q402, T401
RELATIVE CIRCUIT
CHECK T401, T402, Q402, Q403,
D408, C418, C419, H-DY, B+
20
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