Service manual

Buffalo BU1715
39
2. Panel Power Circuit
3. Inverter Control Relative Circuit
NG
Check the Bklt-On relative circuit, R201, Q201,
In normal operation, when LED =green,
Base of Q201 should =0 V,
In saving mode, when LED=orange,
Base of Q201 should =5 V,
OK
Replace Power board
& Re-do white balance
Measured the inverter connector CN102
Pin 1 on/off control=5V (on)
Pin 2 PWM signal control dim 0V-5V
Replace U601
OK
Check R207 should have response from 0V to 5V
When we switch the power switch from off to on
Measured X601 waveform is normal?
OK
Check Q204, Q203 is broken or CN503 solder abnormal?
Replace Q204, Q203 or re-solder CN503
OK
NG
Replace U601
Replace X601
Replace Panel
NG
NG
OK