problem with my footswitch.

[zeppman]

Hey guys. The footswitch (standard one that comes with the amp) on my mark iv started acting up lastnight. When I would try to switch to CH1, it would only work about 10% of the time. I would step on the button and step on the button and it wouldn't switch. Eventually it does, but when I would switch back to ch2 or 3, and try to switch back, the same thing would happen. I can manually switch to CH1 and there were no problems with the sound or anything. But the foot switch seems messed up. Is this something anyone else has experienced? Do you think i just need a new momentary switch to replace that? Thanks guys.

 

[Boogiebabies]

I would think that the contacts in the Ch. 1 foot switch are dirty.
Push down the button and let some contact solvent seep down in there and then push the button 10 times to see if you can clean the junk down in there. They are not sealed switches so the can get grime and gunk in there. If the contacts are totally shot you may need to replace the switch.
You can further diagnose this with a momentary push button switch from Radio Shack and wire it (or clip lead it) in place of the on in there. If it latches the channel every time, call Mesa and get a new switch. The FU-3 is a good footswitch, but when it goes south electonically all sorts of odd things happen. In this case it sounds like a dirty or worn out switch.

 

[zeppman]

Thanks boogiebabies. What kind of solvent? Could you suggest a brand? Thanks!

 

[Boogiebabies]

I use Caig DeOxit and then Caig MCL to lube it. Any decent contact solvent will work to remove oxidation and a bit of grime. Radio Shack now stocks small kits of DeOxit and ProGold for $ 13.00. It's not cheap, but it will get you by if you cannot find any. Auto parts stores usually carry contact cleaner as well.

 

[zeppman]

So i tried the contact cleaner, and it still doesn't work. Anyone know how easy it is to replace the switch? And where can I get the switch?