MC 2200 Won't Leave Mono mode

[JosephH]

I have been running my MC2200 in mono mode for about a year. Last night I went to re-purpose the amp into my 2 channel workshop system and only the right channel (mono channel) had output. The unit comes out of protection, the "Normal" green lights are illuminated on both channels. I exercised the stereo/mono switch on the back about 50 times to no avail. I switched speaker connections and inputs, and the left channel on the amp has no output. I even ran the CD player into the amp directly. There is no question that there is no output on the left channel of the amp. It is almost like it will not come out of mono mode. Both channels worked when I put it into mono service about a year ago.
Has anyone come across this problem before? I thought I would ask before lugging this beast to the local Mc dealer. TIA!

 

[damacman]

Assuming the amp still does operate in mono correctly, it's a safe bet that the Stereo/Mono switch has failed. Typically, it's the other way around - you switch the amp to Mono, parallel the outputs, and then it gets real hot as it's still in Stereo ...

 

[JosephH]

Yes, it sounds great in mono. I will look at the switch. Thanks!

 

[twiiii]

There is an output protection relay where the contacts fail to make a complete circuit after a while. So check the output of both channels in the mono mode separately to make sure they both work, too.