Acer AL707, Руководство по обслуживанию

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16
II (a) THE SCREEN is Abnormal , stuck at white screen, OSD window can’t appear, but
keyboard & LED was normal operation.
At general, this symptom is cause by missing panel data or panel power, so we must check our
wire-harness which connected to panel or the panel power controller (U202)
Check if the Wire harness from CN603 loose?
Check the wire on both Panel-side and Main board side.
Check the Panel-Power circuit as above (page 16)
U202 pin 5,6,7,8 ,must be 5V
Yes, tight enough
Yes, Voltage normal
Check the LVDS-Power L601,L602,L603,L604,L900= 3.3V ?
Check the both U601 & U602 LVDS-Input pin 31= 45mhz –
65mhz, and pin 27 = Vsyn freq, pin 28 = 45khz- 65 khz
Yes, Voltage normal
Yes, Frequency normal
Replace both LVDS chip ( U601 & U602)
Tighten it.
NG
Check U904,which convert the 5V to
3.3V
Check U200 DATA-OUPUT block as
above ( page 16)
NG
Check OSCILLATOR Block as
above ( page 16)
NG, no data output
Replace U302 MCU and check it RESET
pin 10 ,must be turn high to low when first
AC power-on
OK, all clock is normal
Replace U200 GMZAN2
OK, reset is normal
Check U200 DATA-OUTPUT block again
NG, still no data out
NG