Dell 1907FPc Service Manual page 54

No picture (LED is orange)
Measure U601 PIN2=3.3V
X301 oscillate waveforms are
normal
Check if the sync signal from
computer is output and video cable
is connected normally
No picture
U602 PIN2=1.8V
OK
OK NG
NG
OK
Replace U401
NG
Replace U601, U602
Replace X301
Input the sync signal of
computer, or change the
cable
54
Dell 1907FPc