Sony HS75 Service Manual page 42

No Backlight
Check CN902 Pin12 =12V
Check ON/OFF signal
Check IC801 PIN8 voltage is normal?
Check U801 PIN2 triangular wave is
normal
OK
Check U801 PIN4, 5
OK
Check D802, D803, D807, D809
OK
OK
OK
NG
NG
Check adapter
NG
Check Interface board
NG
Check Q807,Q806 circuit
Check C819, C820
NG
Check U801,Q801, Q802
42
HS75 Sony