Keypad Board; Power/Inverter Board - AOC LM2028 Service Manual

INVERTER CONTROL RELATIVE CIRCUIT
Measured the inverter connector CN12
Pin6 on/off control=5V (on)
Pin8 PWM signal control dim 0V-5V
Replace power board to a new one and
check the screen is normal?

8.2.2 KEYPAD BOARD

‚ ñ SN[¶ u 5~ ô O î • D e™ N u(
NG, still no screen
OK
OSD is unstable or not working
Is Key Pad Board connecting normally?
Y
Is Button Switch normally?
Y
Is Key Pad Board Normally?
Y
Check Main Board
QQ:505966338
NG Check the Bklt-On relative circuit, R103, R100, R101,
In normal operation, when LED =green, R101 Bklt-On
should =5 v,
If Bklt-On no-response when the power switch turn on-off,
Replace U402 W78E65P-40
NG
Replace Power board and
Re-do white balance
N
N
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Connect Key Pad Board
Replace Button Switch
N
Replace Key Pad Board
AOC LM2028