BenQ M2400HD Service Manual page 50

24" LCD Color Monitor
(2) No picture
Check if the Pin 3, 4 of CN701 are 5V input
Measure U701 Pin2=3.3V, U702 Pin2=1.8V
Input the sync signal of computer, or
change the cable
No picture
OK
OK
X401 oscillate waveforms are
normal
OK
Check U401
OK
Check if the sync signal from
computer is output and video cable
is connected normally
NG
NG
Check power board
NG
Replace U701, U702
NG
Replace X401
NG
Replace U401
50
BenQ M2400HD