Philips HTS5520 Service Manual page 35

No audio output
No audio output
Check voltage +34V whether normal or not
at XP703 on Amplifier Board
Yes
Check the 22pin FFC connection on Main
Board and XP702 on Amplifier Board
whether right or not between Main Board
and Amplifier Board
1. Check the control signal whether right
or not at the U22'16,17,31,on Main
Board and
XP11'10,11,15
2. Check the audio signal whether right at
the U11'211,213,214,223,225,226,
Yes
Replace Amplifier Board
Go
Yes
the signal at
5-4
Check XP1 pin 7 3.3V on Main Board
No whether normal or not
Refer to XP701 on
Power Board
the
No
Replace U22 on Main Board,or
replace Main Board
Trouble shooting Chart
Yes
No