Denon AVR-3808 left speaker sound problem

Symptoms:

• no sound from left speaker when receiver powers on.
• sound will return after 10 minutes or if volume goes above -15dB
• crackling sound while changing the volume.
• no problem with the headphone connection.

What you need:

• Lots of spare time.
• The service manual of the receiver. You can download it here.
• A soldering iron/station. 

This schematic narrows the problem:

Part of SCHEMATIC OF THE CHANNELS

Remember the part that the headphone did not exhibit the problem... The headphone uses a separate relay: RL108
So it's not the amplifier but one of the relay.

The Cause:

• A failing relay: RL101 DS24D2

Next find the official part number:

And find a shop where they still sell it.  http://www.htv-service-gmbh.de

A few days later in the mail:

So it seems the yamaha genuine parts also work in the Denon, after all it's just a relay.

And now the most difficult part....

The tear down of the receiver:

 We have narrowed the problem, the only thing left to do is to exchange the part....

In the service manual you can find all the steps to fully disassemble the receiver.

Cover removed. 

The RL101 is on the card on the lowest part of the receiver, So we need to remove ALL the cards in  the receiver :( It is a 3D puzzle!

1st part of the 3D puzzle removed

the complete input frame with the complex cards attached removed in one part

RL101 visible, still need to take out the complete board

removed all but front and power-supply

The failing relay on the left , the new relay on the right

the failing relay without the cover

the reassembled 3808