Abnormal Display - HP D8911A Service Manual

1.NO SIGNAL ON SCREEN
CHECK VIDEO IC801 VCC ABOUT 12V
OK
CHECK THE OUTPUT VOLTAGE
OF IC801 PIN 18, 20, 23 ABOUT 3Vpp
OK
CHECK THE B+ VOLTAGE OF
VIDEO PCB ABOUT 80V
OK
CHECK THE VOLTAGE OF CRT
CATHODE ABOUT 40Vpp
OK
CHECK THE VOLTAGE OF FBT SCREEN
ABOUT 400V TO 700V

6-2 ABNORMAL DISPLAY

NG
NG
NG
NG
LESS THAN 400V
EXCEED 700V
CHECK THE 12V PIN
OF P802 CONNECTOR
CHECK THE RELATIVE CIRCUIT
OF IC801
CHECK THE 80V RELATIVE CIRCUIT
OF SMPS ON MAIN PCB
CHECKTHE VQ802 ~ Q807
RELATIVE CIRCUIT
CHECK FBT RELATIVE
CIRCUIT
CHECK FBT & CRT RELATIVE CIRCUIT
OR REFER ITEM 7-1