Lenovo L172 Service Manual page 31

17" LCD Color Monitor
(3) White screen
Check Q406, Q405 is broken
or CN404 solder?
Check Correspondent
component.
White screen
Measure Q406 base
is high level?
OK
NG
OK
Replace Panel
NG
X401 oscillate
waveform is normal
OK
Check reset circuit of
U401 is normal
OK
Replace U401
31
Lenovo L172
NG
Replace X401
NG
Check Correspondent
component.