ViewSonic Q51 series Service Manual page 17

2.ABNORMAL VIDEO LEVEL ON SCREEN
CHECK THE VOLTAGE OF IC801
PIN10/18 ABOUT 5V
OK
CHECK THE SIGNAL INPUT OF
R.G.B
ABOUT 0.7Vpp
OK
CHECK IC801 PIN23 CLAMP
PULSE
OK
CHECK THE VIDEO OUTPUT OF
IC801 PIN19/20/21 ABOUT 3Vpp
AND PIN14/15/16 ABOUT 2V
OK
R.G.B APPROACH STANDARD
3.ABNORMAL DDC (PLUG & PLAY)
CHECK IC101 PIN5 VOLTAGE
ABOUT:5V
CHECK SIGNAL CABLE OR H802
PIN4/5
NG
NG
NG
NG
NG
OK
CHECK 5V RELATIVE
CIRCUIT
CHECK SIGNAL CABLE OR
INTERFACE CARD.
CHECK THE IC801 PIN23
RELATIVE CIRCUIT
CHECK IC801 PIN5/PIN6/PIN7
RELATIVE CIRCUIT
CHECK Q921 GOOD OR FAIL
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