Acer AL2423 W Service Manual page 42

3. Always show "NO SIGNEL"
Change
Cable
VGA Check
R4,R8,R10,R20,
Change VGA
Cable or R4,
R8,R10, R20,
R21 or U7
NO
Yes
R21
NO
"NO SIGNEL"
Check VGA or
DVI Cable
Yes
Yes
Change U7
- 42 -
DVI Check U7
Pin
109, 110, 112,113,
117, 118, 120, 121
NO
Change DVI
Cable or U7