Roland DEP5 no sound... any service manual (DEP5 or DEP3) ?

[Gil]

Hi,

I have a Roland DEP5 multieffect processor which sounds great but has a little problem -
it won't always play audio out... You can see the input meter flashing as it should,
but not always passes sound via the output jacks. It seems to be intermittent as sometimes it will work ok.

I tried cleaning the +4/-20db switch using cleaning spray and it didn't seem to help,
I also noticed that when I push it in or out it will play for a short moment and then the sound disappears...

Any suggestions of how to determine the source of the problem ? battery is new...
Also, if anyone has the schematics or service notes for either DEP5 or DEP3, I would be thankful if could have a copy...

thanks in advance !