HP W19QV Service Manual page 41

19" LCD Color Monitor
2. Panel Power Circuit
Check C501(+) should have response from 0V to 5V
When we switch the power switch from off to on
Check Q602, Q603 is broken or CN501 solder abnormal?
OK
Replace Panel
3. Inverter Control Relative Circuit
Measured the inverter connector
CN601
Pin2 on/off control=5V (on)
Pin4 PWM signal control dim 0V-5V
Replace Power board
& Re-do white balance
OK
NG
Replace Q603, Q602 or re-solder CN501
OK
NG
Measured X301 waveform is normal?
Check the Bklt-On relative circuit, R603, Q601
NG
In normal operation, when LED =green,
Base of Q601 should =0 v,
In saving mode, when LED=orange,
Base of Q601 should =5 v,
41
NG
Replace X301
(14.318MHz)
OK
Replace U401
OK
Replace U401
HP W19QV