No audio output
No
Check the U915 power supply
Check the U916 power supply
(U916.4=-12V and U916.8=12V)
Check whether the audio
signal is right from the
U916.7 and U916.1
Yes
No
Go
Check whether the audio signal
is right from the U915.9,10,11,12
No audio output
Trouble shooting chart
5-2
Replace the U915
Replace the U916
Yes
Yes
Replace the U916