Hi, all--
I purchased a Crate BX-160 amp chassis online (VERY inexpensively), was represented as a working unit, but well, it ain't. Seller is certain that the unit worked perfectly prior to shipment, unit came pretty well packed, bubble wrap and peanuts, etc. Box was unmarked, and there were no obvious signs of shipper abuse. Installed it in a BX-160 cab that I already had. Speaker cab works fine as an extension for my live rig, no issues there.
Unfortunately, the amp is seriously misbehaving--significant hum with or without cord plugged in, signal cuts out, severe distortion with instrument plugged in. I tried three separate instruments, and several different cables. All of the major controls work, and I can hear changes in the hum frequency when I move the EQ sliders. The volume works, but the overall output is abnormally low and heavily distorted, with the exception of pops and crackles that come through strongly enough to activate the limiter LED at what sounds like a more "normal" volume. The amp has an onboard chorus that works, but seems to self-engage at startup, and is buried beneath all of the distortion and hum.
I plugged a different amp's line out into the power in, same results, with the exception of the chorus--low power, lots of distortion, hum, intermittent total signal loss. Tried a different outlet, no change. Swapped all of the cables, no change. Pulled the chassis back out, no obvious issues--caps all look good, no burn marks, no loose wires, no smell. Didn't seem to run hot. My best guess is that something is wrong with the power amp, but I don't know where to go from here.
Any thoughts on causes that I can check? I have a basic working knowledge of electrical componentry but haven't really spent a ton of time in amps. I'm likely to take this to a pro for repair, if it's repairable, but I'd like to be able to diagnose a bit beforehand so I know what to expect.
Thanks so much!
I purchased a Crate BX-160 amp chassis online (VERY inexpensively), was represented as a working unit, but well, it ain't. Seller is certain that the unit worked perfectly prior to shipment, unit came pretty well packed, bubble wrap and peanuts, etc. Box was unmarked, and there were no obvious signs of shipper abuse. Installed it in a BX-160 cab that I already had. Speaker cab works fine as an extension for my live rig, no issues there.
Unfortunately, the amp is seriously misbehaving--significant hum with or without cord plugged in, signal cuts out, severe distortion with instrument plugged in. I tried three separate instruments, and several different cables. All of the major controls work, and I can hear changes in the hum frequency when I move the EQ sliders. The volume works, but the overall output is abnormally low and heavily distorted, with the exception of pops and crackles that come through strongly enough to activate the limiter LED at what sounds like a more "normal" volume. The amp has an onboard chorus that works, but seems to self-engage at startup, and is buried beneath all of the distortion and hum.
I plugged a different amp's line out into the power in, same results, with the exception of the chorus--low power, lots of distortion, hum, intermittent total signal loss. Tried a different outlet, no change. Swapped all of the cables, no change. Pulled the chassis back out, no obvious issues--caps all look good, no burn marks, no loose wires, no smell. Didn't seem to run hot. My best guess is that something is wrong with the power amp, but I don't know where to go from here.
Any thoughts on causes that I can check? I have a basic working knowledge of electrical componentry but haven't really spent a ton of time in amps. I'm likely to take this to a pro for repair, if it's repairable, but I'd like to be able to diagnose a bit beforehand so I know what to expect.
Thanks so much!