Need help to refurbish/repair Mesa Mark IIB

[TheHysteria]

Hey,

Actually, I don't think there is a fan on my Mesa Mark IIB. I unplugged everything though. But yeah, the screws are still kind of awkward. I unloosened the rest, but it doesn't work. The last screw is not extremely tight, but at the same time it's a difficult to pluck it out with your hands/pliers. It's like half-in and half out?

The weird thing is the chassis is pretty stable. I tilt it back and forth and it didn't come out. I also tried pushing it. If the top screw on the chassis is loose, is it still safe to plug and play it?

 

[stokes]

Are you saying you cant get it out because it is stuck or just difficult to grab because you cant get your fingers in the recess?Maybe the nut on the chassis is misalligned.It should be okay to play like that but I would want to know why it wont thread properly.Why not take the chassis out again and investigate,now that you've done it once you know how so it shouldnt be a big deal.One of the screws should have a grounding washer the screw has to pass thru to connect the chassis to the shielding inside the top of the cabinet.Get the screw out and remove the big black washer and you should see what looks like a small lockwasher with a piece of bare shielded type wire attached.Maybe that isnt lined up right and it is impeding the screw.It may not be on that screw but take a look unless you know for sure it is on another screw.Check that before removing the whole chassis again.

 

[TheHysteria]

Oh, it's just difficult to grab out. I don't know it doesn't seem like a big problem and Mesa/Boogie also said there shouldn't be any long-term effects. The chassis is sturdy and I just played it for about 45minutes (Awesome tone, by the way).

I might leave it alone for now and personally I don't want to take out the chassis again.

You guys did say 'don't turn on the amp if something is in the chassis' (ie. t-nut). (I didn't hear anything inside the chassis when I tilted it back and forth-unlike the t-nut that was moving around). This is a different scenerio right, because there are no t-nuts for the top 4 screws.

 

[TheHysteria]

I agree, What ever you do DO NOT PLUG THAT AMP IN UNTIL YOU HAVE SOMEONE GET THE NUT OUT!!!!! KABOOM!!! MONEY MONEY MONEY!!!!!

Well I took it out, but just for my information.

Is it possible for that t-nut to short something out while the amp is NOT turned on?

I just gave it a 45minute drive and it sounded good, but just wanted to make sure.

 

[stokes]

No,as long as the amp wasn't used with the nut loose inside you will be okay.The screws holding the chassis in the cab connect to a nut that is fixed in place in the edge of the chassis,it shouldnt be able to fall into the chassis unless the nut retainer broke loose.But you would hear it rattling around in the chassis.Your next post you say "you took it out,but just for my info".I assume you mean you removed the chassis again.Did you figure out why it wouldnt screw in properly?

 

[TheHysteria]

No,as long as the amp wasn't used with the nut loose inside you will be okay.The screws holding the chassis in the cab connect to a nut that is fixed in place in the edge of the chassis,it shouldnt be able to fall into the chassis unless the nut retainer broke loose.But you would hear it rattling around in the chassis.Your next post you say "you took it out,but just for my info".I assume you mean you removed the chassis again.Did you figure out why it wouldnt screw in properly?

Oh thanks for the explanation. Man, Mesa should have made the handle nut fixed in place as well. That would have saved me a lot of trouble, but I guess you just learn these things.

Anyways, no, I didn't take the chassis out the 2nd time. I emailed Mesa and they told me it should be fine as long as it's not touching the chassis. I have a feeling that one screw lost 'teeth' that's why it couldn't grip and bolt on properly to the chassis. I played it today and couldn't hear anything wrong so far. If there's a problem, I'll get it fixed.