Interface-Board Trouble-Shooting Chart - Acer AL707 Service Manual

6 A). INTERFACE-BOARD TROUBLE-SHOOTING CHART
*Use the PC Win 98 white pattern, with some icon on it, and Change the Resolution to 640x480 60 Hz / 31 KHz
**NOTICE : The free-running freq. of our system is 48 KHz / 60 Hz, so we recommend to use another resolution
to do trouble shooting, this trouble shooting is proceed with 640x480 @60Hz 31Khz
I. NO SCREEN APPEAR
Measured Input DC-voltage ( J1)= 12 V?
Measured U305 AIC 1084 pin 2 = 3.3V?
Measured U904 LT1117 pin 2= 3.3V?
Measured U905 RT9164 pin 2=2.5v
Disconnected the Signal cable( Loose the
Signal cable ),Is the screen show "Cable Not
Connected" ?
No, nothing is show
Connected the Signal cable again,
Check LED status.
Led Green
Check the Wire-Harness from CN603
was tight enough?,
check the Wire connection to panel side too
OK,Wire tight enough
Check Panel-Power Circuit Block
OK,Panel Power OK
Check U200 Data-output Block
OK, U200 data OK
Replace Inverter and Check
Inverter control relative circuit
Re-do White balance adjust
OK
Note: 1. if Replace "MAIN-BOARD" , Please re-do "DDC-content" programmed & "WHITE-Balance".
2. if Replace " INVERTER" only, Please re-do " WHITE-Balance"
DC-Power Part
Yes, all DC level exist
Led Orange
Check Power switch is in Power-on
status , and check if Power switch had
been stuck ?
OK, Keyboard no stuck
Measured RGB (r200,r201,r202) H,V Input at U401
pin 9 ,4 ,was there have signal ?
OK,input Normal
Measured Oscillator Block
Oscillator U201 & Crystal X300
Check communication pin between U200 &
MCU pin 2,6,7. , is it have transition?
OK, Mcu have transition
Replace U200 (Gmzan2)
OK
14
Check Correspondent component.
Is there any shortage or cold solder?
Yes, there have OSD show
Connected the Signal cable again,
Check LED status.
Led orange
OK,clock normal
Replace U302 (MCU)
& check Reset pin 10
must be change from High to
low when first AC power plug-
in
Led Green
Replace MCU
NG Check Correspondent
component short/open
( Protection Diode )
and Signal cable
bad ?
NG, no transition