Mesa Boogie Mark III Redstripe Problem

[metalhead3ecr]

Hey guys, new to the forum...hoping you could help me out.

http://www.youtube.com/watch?v=WlqkEJF1NJw

What is wrong with the amp? I have been told it is a capacitor in the EQ circuit. I can take pictures of the inside if need be.

I will be gone this week so bare with me if responses are slow.

Thanks,
Ed

 

[>Photi G<]

The EQ switch/LDR/both are probably past it. It sounds like the EQ is disengaging momentarily, which leads me to believe that it's a switching problem, not a component in the signal path.

 

[Rob Lockwood]

+1. I would be looking for a loose connection somwhere in the switching circuit. It could be a failing LDR either, I'm not sure whether those are likely to fail intermittently like this or not. If the eq is working and adjustment of all sliders gives the effect on tone that you would expect, but just alternating between on and off I would suspect the connection/bad solder joint first. You could try setting the eq to an extreme setting so its obvious whether its on or off and banging the top of the amp with you hand whilst playing. If mechanical shock seems to cause the EQ to go in or out again it suggests a connection issue.

If you have a footswitch plugged into the EQ on/off jack then intermittent faults with the switch/cable would be a possible cause too.

 

[metalhead3ecr]

Thanks! I think it is something to do with the switching. I will look into it!