ViewSonic P774B-2NT Series, Service Manual

Page: 17 / 45

16
6-3 NO BLANKING
NG
OK
CHECK THE RELATIVE
CIRCUIT OF BLANKING
CHECK THE RELATIVE CIRCUIT
CHECK R846 ON VIDEO PCB,
CHECK G1 RELATIVE CIRCUIT
FBT PIN 5 ON MAIN PCB
OF Q705
6-4 HOR./OSC/DEF/HV CIRCUIT FAULT
1. NO RASTER (DISCONNECT WITH SIGNAL CABLE)
NG
OK
OK
OK
NG
NG
NG
CHECK THE COLLECTOR VOLTAGE
CHECK THE COLLECTOR VOLTAGE
RELATIVE CIRCUIT
RELATIVE CIRCUIT
CHECK Q402, T401
CHECK T401, T402, Q402, Q403,
ABOUT 3Vpp
OF Q403 ABOUT 1200Vpp AT FH:31KHz
D408, C418, C419, H-DY, B+
CHECK IC401 PIN 26 WAVE FORM
CHECK IC401 PIN 4~7, PIN 13
CHECK IC401 PIN 29 ABOUT 12 VDC
CHECK IC401 PIN 29 RELATIVE CIRCUIT
OF Q402 ABOUT 20Vpp