Acer AL1921 Service Manual page 48

4.U602-Data Output
Measured DCLK(R240)DVS, DHS (pin 117,116 from U203 )
Is the waveform ok?
DCLK around 48 MHZ , DVS=60.09Hz , DHS around 80
KHz ?(refer to input signal=640x480@60 Hz 31k, and LED is
Green)
Check U203 MST8131B, Signal output
ER0~7,EG0~7,EB0~7,OR0~7,OG0~7,OB0~7, Is the
waveform ok ?
heck U301,U302 LVDS IC Signal output
OK
OK
OK
Replace MST8131B (U401) or
replace MAINBOARD.
If MainBoard being replace , please
do the DDC – content
Replace U301,U302 LVDS IC or
replace MAINBOARD.
47
NG , no transition