Problem with my Markbass Mini CMD 121P IV

[vinylphile]

Hey all,

I recently acquired one of these nice combo amps used. Unfortunately it was a bad Kijiji deal and the amp seems to have a problem. Of course the guy didn’t respond to any of my post-sale messages. Another Kijiji lesson learned…

In any event, the problem is the power switch. Sometimes when I flip it on the amp turns on and then shuts itself down within a minute. If I push on the switch I usually feel a slight click and the amp goes back on. The problem seems to be worse when I have a cable plugged into the adjacent footswitch jack.

Anyone know what the problem may be and how easy it may be to fix? The amp is less than a year old. I emailed the local distributor about service last week but haven’t heard back yet.

Thanks in advance!

 

[Old Garage-Bander]

Well it could be a faulty power switch. Or could be a bad wiring connection at the power switch.

When you push on the switch and the amp comes on, does it stay on as long as you continue pushing, and then does it go off when you stop pushing?

How are you pushing?
On just the switch actuator?
On the part where the switch contacts the panel?
Pushing straight in, or to the side?

The only connection that I can think of between foot switch jack and power switch, would be if the plug in the FS jack is stressing the switch or it's connections mechanically. But that would require a lot of force or a very flimsy panel.

Try using something smaller, like a pencil to do the pushing (Only from the outside). This might help isolate how you need to stress it to make it work.
Likewise use the pencil to push the plug around in the FS jack and see it that has any effect.
Use as light pressure as needed to get a reaction.