Meas Nomad 55 trouble ?

[jads57]

Hi, I just received a Mesa Boogie Nomad 55 in trade from a fellow member. Unfortunately, it must have taken a bump or two courtesy of UPS. The tone controls in ch. 1 don`t work at all. And the treble control in ch.2 only works when full on or off. After tightening the knobs, now ch 2 also has significant volume loss. Any ideas, or does it need to go to a pro. technician? Thanks in advance for your help. jads57

[Blue Strat]

Sounds pretty serious and not a user serviceable type of thing.

[Rich M]

Wait! I had this problem with a Nomad 55 and it is one of two things. 1.) Faulty pots. Record the serial numbers on the back of the pots and call mesa. They can tell you if they were part of the bad lot. 2.) (the problem I had) Mesa had a issue that if the knobs were pushed inward, the knobs, not contacting the pot's bushing, would allow the shaft to push onto the back of the crimped can inside causing it to loosen up and that would make the wiper lose contact. The way to test for this is to pull the knob in and out and if there is any slop, if so the can is loose. Solution is to (after properly discharging HV caps) remove the pots and recrimp pot cans. Also, if that is the problem, Mesa has little nylon bushing that snap into the backside of the knob to prevent this from happening.

Hope this helps. Great little amps!

[jads57]

Thanks Rich, I`m not sure how to discharge the HV caps though. So, I guess I`ll take it to a pro.

[Rich M]

The right thing to do. If the pots are loose and not defective, you might want to call mesa and get a set of the corrective washers so your tech (or you - they fit on the backside of the knob) can put them on before the cans are recrimped. That way you won't risk banging a knob and loosening them back up.

[jads57]

Thanks again to Mike and Rich for the suggestions. I`ll call Mesa and bring it to a tech w/ your suggestions. jads57

[LesPaulMan]

I had the same exact problem with my Nomad 100. Rich M's description of the pot problem is right on the money. The depth of the knobs was short, leading to the pots being stressed if you put any pressure on them.

I'll just add that this problem only happened on the early Nomads (first year or two, which was perhaps around 1999/2000ish.) The knobs were then re-designed to eliminate this problem.

[jads57]

Thanks Les Paul Man, this really helps a lot. I think forums like this are great to find out info. you would`nt be able to otherwise. jads57

[jads57]

I ended sending it back to Mesa Boogie to get repaired. They said it would run about $100.00 to replace the bad pots with new ones. Thanks again to everyone for their help.You all were definitely correct about the diagnosis.