i recently picked up a crate gx-130c combo amp and my problem is it'll switch channels while playing, making a really bad hiccup sound.

ive noticed it happens mostly when im playing loud or when the drums are going. so is this a simple loose wire getting knocked around from the vibrations or is this a bigger problem? ive never attempted to fix an amp so im definately skeptical about opening it up and trying to wing it...so any kind of help/advice will be greatly appreciated.
Does it have a footswitch?
If so, unplug it the switch, play loud or with drums like usual, see if it continues to do it.

If not, it's in the footswitch. Get a new one, or take yours apart and look for trouble.

If it still does, pull the chassis and look for loose/cracked solder joints and connections or take it to a tech.

EDIT: have you tried using the amp on different circuits or different locations?
Low voltage or intermittent voltage drops at the wall can trip FET switches or make them act up...
Last edited by Rutch at Nov 24, 2009,
theres no footswitch but i pulled out the chassis and looked around for anything loose or cracked and i didnt find anything wrong with it. (i could of easily missed something though)

i used several different wall plugins with no luck at all..
Could be dodgy solder joint,footswitch jack, or possibly the PCB has flexed (usually due to heat buildup inside the amp) and damaged a connection.

You could take it to a tech, although repairs on cheap solid-states are often very complex and not worth the money.
Incidentally, this seems to be a very commobn problem with the GX-130c (google it and you'll immediately find people complaining of the same problem).

Here's a post I found from Jemsite:

So I took it apart. Checked out some of the solder spots...turns out this amp has a life of about 10 years (check out harmony reviews on this amp and I'm not the only one having this problem). I narrowed it down, to what I thought, was the channel selector button, since this was, as I believe it to be, a simple on/off switch, I took another switch from the same amp and switched them out (one that I didn't use, I think it was the line selector for effects out or something. I don't use it, so I switched it out.)

That ended up not solving the problem. I found out that there is a power line connecting the two circuit boards in this particular amp...it's red with about 10 wires coupled into a 10 wire plug. Took out the plug, sprayed it with contact cleaner, let it dry, put it back in, but it was still acting up, much less than before but still acting up...I jostled the fourth wire (from the front of the amp) and that was indeed the source of the problem. I cut some insulated wire and bound it to this "loose" wire and now there are no problems. Had a gig yesterday and played loud as hell and no hiccups at all.

This symptom is a result of playing loud enough to cause reverberations within the amp, causing that wire mentioned above to become loose.

I am not eletrically savvy, so if anyone knows what this all means, would be more than glad to hear it...whatever I did, or didn't do, it is working now.

I hope this info helps others.

I went and cleaned it with spray cleaner and noticed a few of the power wires barely hanging on to what they were connected too so i made them all secure, i also checked the red 10 wire plugins and they were all fine. i thought this would fix everything but after about 20 minutes of playing nice and loud the hiccups came right back...

the weird thing is it consistently lasts a good 15-20 minutes before the hiccups start so i doubt its a loose wire anywhere, im guessing its a heating problem?