HP Compaq L1702 Service Manual page 40

2.) W / LED , No Backlight
Check CON102 Pin12 =12V
Check ON/OFF signal
Check U201 pin9=12V
Check the pin1 of U201 have saw tooth wave
Check D201(-),D202(-) have the output of
square wave at short time.
Check the resonant wave of pin2 & pin5
for PT201/PT202
Check the output of PT201/PT202
Check connecter & lamp
OK
OK
OK
OK
OK
OK
OK
Page 40 of 143
HP L1702/FP7317 Service Manual
NG
Check adapter or MB
NG
Check Interface board
NG
Change Q201 or Q202
NG
Check C208,R204, U201
NG
CheckU201,Q203,Q204,Q205-Q208,
ZD203,ZD204
NG
Check Q209-Q212,C213,C214
NG
Change PT201/PT202