Acer X241 Service Manual page 55

3. Always show "NO SIGNEL"
Change
Cable
VGA Check
R4,R8,R10,R20,
R21
Change VGA
Cable or R4,
R8,R10,R20,
R21 or U7
"NO SIGNEL"
NO
Check VGA or
Yes
NO
DVI Cable
Yes
Yes
Change U7
DVI Check U7
Pin
109,110,112,113,
117, 118,120,121
NO
Change DVI
Cable or U7