Problems with Jet City JCA100H

[Alvin_Wilson]

I have a Jet City JCA100H and I'm having issues with it. I had it listed for sale/trade on Craigslist about 6 weeks ago and forgot about the listing. This guy contacts me and wants to buy it but he is in north Ga about 2 hours away from me. He wants to be sure the amp works before he drives down to the Mall of Ga to pick it up. I told him I would send him a video so he can be sure he wants it. So I fire it up last night for the video and I get a lot of popping/cracking and the volume cuts in and out. I swear I can smell a not-so pleasant aroma coming from the head, but no smoke. I haven't had it on in a few months so I had no idea this was going to happen. I keep it under the dust cover so it's not dusty. Any of you amp specialists know what is going on? Tubes bad? I checked my cords on my Vetta and had no issues with them.

I messaged the guy and told him what I was experiencing and that I could not with a good conscience sell him the amp. Any help/suggestions are appreciated.

[charvelguy]

first culprit to check is a bad output tube. http://www.guitarhow.com/32_guitarho...intenance.html

[jgcable]

The smell could just be the tubes warming up. Try cleaning the send and return jacks for the effects loop. Then.... take a pencil and tap each tube with the amp on and see if any of them make a funny noise. Let me know what happens.

[Alvin_Wilson]

Thanks guys. I'll let you know what I find out.

[Shawn Lutz]

sounds like possibly a bad output tube. Was it the burnt electronic smell or just tubes heating up? You may have fried something if it was the toasted resistor smell

[charvelguy]

ya, it could be a circuit board issue (link heating up and breaking) or a grid resister heating up and causing the former before the fuse blows.

here's another link addressing the problems associated.

http://www.premierguitar.com/Magazine/Issue/2009/Jan/Diagnosing_a_Distressed_Tube_Amp.aspx