Speaker pop on amp startup - 1 channel only

I have an amp (Sony TA-N90ES) that makes the left speaker only pop as it comes out of protection. With a VOM I measure about 5VDC on that channel for a split second, quickly diminishing to zero.

I got a very good deal on this amp because of this but I would like to figure out what is going on. Any suggestions? It is a solid state MOSFET amp.

Leave it on!
4est -

That is what I plan to do but I would like to figure it out - I want to know if it is something that would affect sound quality or if it is just the equivalent of a cosmetic issue.

Sorry for the jest, but I imagine there are many things that could do it. Without a schematic it is hard to tell. I tend to leave SS gear on regardless. Leave it on or get it fixed, lest you take out a driver passing DC. I'd have it looked at straight away myself, in case there is some sort of bias mismatch or a part nearing failure -even if it sounds "right".
I did check the bias and it measures OK as specified in the service manual. Also the left speaker terminal measures 0 volts DC ~2 seconds after exiting protection mode - the right one always measures 0.

It was checked out by Desco Service Company of Olympia, Washington and they said it was OK other than the popping.

How much DC does it take to damage a driver? Won't a high pass filter block DC?

I may take it in to United Radio in Syracuse NY and have them look at it. In the meantime I my friend at work is going to look at the schematic and see if he can identify any likely culprits.

The cap in the tweeter will protect it. 5v is not much DC at the output. It could be as simple as the relay sticking on that channel or a bad cap.
Does it do it when the preamp is off?
Rwwear -

I believe so. It does it when there is nothing connected to the inputs.

Then it has to be the amp.