Mark III technical problem - won't turn off

[BMcNibbnles]

I have a red stripe Mark III head with graphic EQ and reverb. Over the past few months, it has been doing this strange thing where, when you turn off the power switch, it doesn't turn off. At first, it'd work after turning the power switch on and off a few times and eventually it'd finally shut off.

Today, however, at band practice, the amp functioned perfectly fine ..... no dropouts, no bad tone, nothing out of the ordinary..... but, when I tried to power it down, it wouldn't power down AT ALL. The power and standby would be off, but the amp's blue light was still on and you could tell that the amp was still on, although no sound would come out because the standby switch still works. If I turn on the standby switch, I can get sound. So, I think the problem is only with the power switch and not the standby switch.

Any ideas?

 

[Whoopysnorp]

Might just be a physical problem in the switch. Those things will wear out eventually.

 

[zodiac272]

Maybe somebody died while it was on the production line... Is the amp nicknamed "Christine"? spooky.

but yeah, sounds like you need a new switch

Scott

 

[BMcNibbnles]

Yeah, that was my first (and, most obvious) thought. Thanks for your thoughts. One more thing: is this an expensive fix?

Oh, and one last thing, actually - I'm really considering sending this amp to Mesa to have them go through it and clean it out. Everyone speaks very highly of how they do that, so I'm thinking about it. What does that cost and what do they do to the amp?

 

[dodger916]

Yeah, that was my first (and, most obvious) thought. Thanks for your thoughts. One more thing: is this an expensive fix?

A new power switch should be pretty inexpensive to have installed. Unless you really know your way around a tube amp, I would NOT recommend trying it yourself. Touch the wrong thing and you could get fried, even with the unit unplugged.

Oh, and one last thing, actually - I'm really considering sending this amp to Mesa to have them go through it and clean it out. Everyone speaks very highly of how they do that, so I'm thinking about it. What does that cost and what do they do to the amp?

They'll look to replace old capacitors and worn out resistors, adjust or replace worn or loose tube sockets, clean/lube graphic eq sliders, etc; general maintenance items. This usually runs about $200 plus two-way shipping.

I would personally recommend Board member Boogiebabies for work on an early Mark amp. His prices are about the same, and he will blueprint the amp. He did an amazing job on my C+, calling me frequently to discuss mods he could install. It's like having a good friend who loves these amps working for you.