Trouble Shooting; Main Board - HP L1740 Service Manual

17" LCD Color Monitor

9.2 Trouble Shooting

9.2.1 Main Board

1、No power
No power
Press power key and look if the
picture is normal
NG
Please reinsert and make sure the
AC of 100-240 is normal
OK
Measure U204 PIN 2=3.3V
U202 PIN 2 =1.8V
OK
Y301 oscillate waveforms are
normal
NG
OK
Replace U401
NG
NG
Measure CN401 PIN9/10=5V?
Replace Y301
28
Reinsert or check the
power section
OK
Chec Check power section
TXD
NG
Replace U204/U202
HP L1740