rapid channel switching problem

[nsnyder]

My Mark V head started acting strange today, mainly involving the eq and channels 1 and 3. When I have the 5-band eq on both channel 1 and channel 3 and I switch to channel 3, the relays will start chattering and the amp will cut out as it tries to rapidly switch between channels 1 and 3. Another symptom is that the eq will not turn on and off using the footswitch on any channel.

It hasn't occurred under any other circumstances and happens with the pedal plugged in and without it. I rarely use the eq on channel 1 or switch the eq in or out with the footswitch, so it's not the end of the world, but I'm curious as to whether anyone else has encountered this and how crazy an issue it was to have repaired.

I bought this amp used and this will be the second time it has been to the shop for repairs in less than the year I've had it. I have a sinking feeling because I love it, but I worry it may have bigger problems than I want to deal with.

 

[etepbbb]

I've had problems like that, I think mine was the result of the pedal cable not seating properly. I had it in the repair shop, they couldn't isolate a problem. Which, it's hard to troubleshoot an intermittent issue, at this point I haven't had a problem in some time. I'd look at the cable connection to the amp and pedal. You mention having the same issue with the pedal disconnected, I'm guessing the cable still connected to the amp perhaps causing the issue. I won't worry to much about having a lemon, the cable issue is kind of a known.

 

[fr0sty]

Yep, it's the foot switch cable not being seated into the foot switch all the way.

 

[bandit2013]

It should not do it with the footswitch removed. I use my Mark V without the footswitch because I am lazy and change channels with the rotary knob on the back of the chassis. Yes, I have switch to the footswitch position and it just jumps to CH3 by default. I will use the footswitch every now and then.

The footswitch setup is not ideal with this amp for some reason or another. Never had any issues with the Roadster and it also uses the 8 pin cable.