17
6-2 ABNORMAL DISPLAY
1.NO SIGNAL ON SCREEN
CHECK FBT RELATIVE
CIRCUIT
LESS THAN 400V
OK
NG
NG
OK
OK
NG
OK
NG
CHECK THE OUTPUT VOLTAGE
CHECK THE B+ VOLTAGE OF
CHECK THE VOLTAGE OF CRT
CATHODE ABOUT 40Vpp
CHECK THE VOLTAGE OF FBT SCREEN
CHECK THE RELATIVE CIRCUIT
CHECK THE 12V PIN
OF SMPS ON MAIN PCB
RELATIVE CIRCUIT
OF P802 CONNECTOR
ABOUT 400V TO 700V
EXCEED 700V
OF IC801
CHECK FBT & CRT RELATIVE CIRCUIT
OR REFER ITEM 7-1
VIDEO PCB ABOUT 80V
CHECK THE 80V RELATIVE CIRCUIT
CHECK VIDEO IC801 VCC ABOUT 12V
OF IC801 PIN 18, 20, 23 ABOUT 3Vpp
CHECKTHE VQ802 ~ Q807