Fujitsu Siemens Computers B19-2 Service Manual page 38

No backlight
Check U201 pin9=12V voltage
Check the pin7/10 of U201 if have waveforms
Short Q203/Q204 if the picture normal
Connect PIN15 of U201 to the ground and check Q209/Q210/ Q211/Q212 collector waveforms
Check feedback circuit
Check C201 (+) =12V
OK
Check ON/OFF signal
OK
OK
NG
OK
NG
OK
NG
Check F201
Check D201/Q209/Q210
NG
Check Interface board
NG
Change Q201 or Q202
Change U201
NG
Change Q209/Q210/PT201
Change Q211/Q212/PT202
Check connecter & lamp
Page 38 of 55
NG
FSC B19-2