![](/images/new-backgrounds/1249440/24944033x1.webp)
PANEL-POWER CIRCUIT
check R225 should have response from 12V to 0V When we switch the power switch from on to off
OK,R225 have response
NG
Check the PPWR panel power relative circuit, R223, Q200,U202(pin 5,6,7,8)
In normal operation, when LED =green, R223 should =0 v,
If PPWR
Measured the U202 pin 5,6,7,8= 5 V?
OK
OK
NG, no Voltage
Yes
Check U202 pin 1,2,3,4= 5V
Replace U202 ( Nmos, SI9933)
NG
Check U304 relative circuit.(R905,T300..)
INVERTER Control Relative Circuit
Measured the inveter connector CN303 Pin 1=12V, pin 3 on/off control=5V (on)
NG, still no screen
Replace INVERTER to
OK
NG
NG
Check the
R315
If
Replace
OSCILLATOR BLOCK
Measured U201 Oscillator output R215= 50mhZ ?
OK, has transition
Measured X300 Crystal output R340= 20mhZ ?
OK
U200-DATA OUTPUT
Measured PCLK(L207) PVS,PHS (pin 73,74 from U200 ) Is there have any transition? Pclk around 47MHz to 57MHZ , PVS=60.09Hz , PHS around 67 KHz ??(refer to input signal=640x480@60 Hz 31k, and LED is green)
OK
NG,no transition
Replace Oscillator U201
NG,no transition
Replace Crystal X300
NG , no transition
Replace GMZAN1 (U200) or replace
MAINBOARD.
If MainBoard being replace , please do the DDC – content reprogrammed
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