Help: HK 135 with popping channel

My Harmon Kardon AVR 135 is having issues with the right surround channel.

Our in-ceiling right surround speaker has been broken for a year or so, and I just got around to replacing it. Unfortunately, what I found when I did is that there was also something wrong with the channel coming from the amp.

The issue is a popping/clicking sound that happens every time the sound stops– either from pausing, muting, or just from a song ending.
Linked is a video of the problem in action.

My question is: Is this a problem that can be/would be worthwhile to be fixed? Who would I send it to? What would the cost be like? Etc.


Have any of you seen anything like this before?

Thanks for your help,
Zach

Anyone have any advice?

Budwich,

It's already been determined that the problem will follow that channel as I pass it from speaker to speaker. What is to be gained by this experiment?

Also, the other speaker's problem was caused by someone stepping on it – not the amp!

Thanks for your input though!