Troubleshooting a sound-equipped loco

[R L Smith]

I have a sound-equipped PCI E7 that I haven't had issues with -- until now.  I had taken the shell off to see if a Kato E-8 shell would fit (it does not, at least not without some mods), and ran the loco for awhile without any shell.  After less than 5 minutes, the sound stopped.  Loco runs fine, headlight works fine, the sound just stopped.  I removed it from the track and put it back on, and had a moment of sound - then silence.  It responds to commands, as I can still control the speed, direction and headlight.

The manual doesn't help much.  So far I have done a factory reset on the programming track, cleaned the wheels, and cleaned much of the track, none of which have restored the sound.  Lightly tapping the chassis and the circuit board were ineffective too.

Any thoughts?  I was just getting ready to put this up for sale, so disappointing doesn't begin to describe the emotion right now.

[Cajonpassfan]

I had a similar problem with one of my PA's and it turned out to be an internal fuse that needed resetting. As I recall, and it's been a while, there is a tiny rectangular push in switch on the decoder (kind of like a micro miniature RFI reset on your bathroom receptacles). It would be nice if it were that simple, huh?
Good luck, Otto

[Bob Horn]

Which verson/decoder do you have?

[peteski]

Which verson/decoder do you have?

Yeah, that would be helpful info! 
It might also be possible that a speaker wire somehow got disconnected....

[R L Smith]

Problem solved!!  Thanks to all who responded.

While looking for a 'reset' switch per Otto, I discovered that the two PC boards had become slightly separated.  Once I gently pressed them back together, everything is fine.

Thanks again!

Ron