Abnormal Display - ViewSonic Q51 series Service Manual

6.2 ABNORMAL DISPLAY

NO SIGNAL ON SCREEN
CHECK VIDEO IC801 VCC ABOUT
5V
OK
CHECK THE OUTPUT VOLTAGE
OF IC801 PIN19/20/21 ABOUT 3Vpp
OK
CHECK THE VIDEO 80V OF IC802
PIN4 ABOUT 77V
OK
CHECK THE VOLTAGE OF CRT
CATHODE ABOUT 40Vpp
OK
CHECK THE IC803 PIN6, 7,8 VOLTAGE
ABOUT 50VDC RELATIVE CIRCUIT
OK
CHECK THE VOLTAGE OF FBT
SCREEN ABOUT 400V TO 700V
NG
NG
NG
NG
NG
LESS THAN 400V
EXCEED 700V
CHECK THE 5V PIN OF P802
CONNECTOR
CHECK THE RELATIVE CIRCUIT
OF IC801 PIN23 CIRCUIT
CHECK THE 80V RELATIVE
CIRCUIT OF SMPS ON MAIN PCB
CHECK THE IC802 RELATIVE
CIRCUIT
CHECK THE IC803 RELATIVE
CIRCUIT
CHECK FBT RELATIVE CIRCUIT
CHECK FBT&CRT RELATIVE
CIRCUIT OR REFER ITEM6-1
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