Preamp no volume when cold

[Jslimjeff]

I have a Denon AVP A1HDCI 7 channel preamp that is causing issues. When powered up and cold the audio output volume is low. There is no low end or mid bass, after several hours it starts to get better but not to original levels. What should I be looking at for causes. Capacitors do not show any visible signs of fault.

 

[rayma]

Probably it's still an electrolytic capacitor problem. If it's been unused for a long time,
the capacitors may come back further after some more hours of operation.

 

[Mark Tillotson]

Cold spray might help localize a temperature-sensitive fault.

 

[Douglas Blake]

This unit is a real beasty.

Because of the complexity of the unit I would absolutely not recommend sticking my fingers in there without the service manual and a fair bit of experience in troubleshooting LSI chips and digital audio.

I went looking for the service manual and could not find it at any my usual spots.

I think your best bet is to take it to a qualified technician...