I have recently acquired a set of three speakers/subwoofers, and an old Bogen Amp. Now, I followed the person who give me the Amp directions, and hooked up my PC to the Amp using an adapter, using the 8-ohm and ground jacks for my connections. Two speakers have a maximum input of 120 volts, and the other, 80. I did not crank the amp up, just full volume on the computer and 2/10 power from the Amp. It lasted ten minutes before dieing. I have tried removing all wires and cables from the Amp, and have tried resetting the circuit breaker as well. Nothing happens when I reset the breaker, other than a split second of the power lamp coming on, and then the circuit breaker trips. Any idea of what happened and what parts I might need would be very helpful. Thanks for your time!
No, not really. The guy that "gave" it to me repaired it once before leaving it in his garage for a couple of years to collect dust. He's a teacher at my school, and he does all the hookups for the Amps and speakers for the auditorium, ect. Just want to find out the problem so I can figure out a price range to buy the part, and to pay him for his time, depending on the difficultly.
It's impossible to diagnose a problem over a forum. If the unit has been stored for several years, there could be a multitude of caps that have gone bad. Filter caps are the most likely suspect for this problem but any amplifier can have multiple coupling caps that will stop a unit dead. If coupling caps aren't the problem this time, which they probably aren't, they could cause problems in the future. A bias resistor could be affecting the unit to the point of pushing it into protection.
If this is a tube amplifier, you need to make certain all the tubes are operating as they should. If the rectifier tube has crapped out, then the amp will no longer work. Connect a load across the outputs, either a cheap speaker or a large 20 Ohm load resistor to the 8 Ohm tap and ground and power the unit up. In a darkened room, check for each tube coming up to a bright but not firey, cherry red glow. If the unit won't operate long enough for the tubes to come up, then you probably have a power supply cap that has gone bad or a diode that has gone South.
If the unit is solid state and it will not power up, there could be nunmerous circuits that might cause a shut down but the power supply is still the most likely suspect when an amp will not operate at all. There's no way to tell, however, without getting your hands into the unit. Don't do this unless you know what you should not touch - which is pretty much anything inside the amp if you don't know what's safe to touch. There are lethal voltages inside the amp, so don't try anything that could quickly result in you never hearing anything ever again.
To do diagnosis and repairs plus parts, most any shop would probably be charging somewhere between $100-200. Is this amp worth that much to you?
I also had all three speakers on a single load, connected to the 8-omh and GND, could it just be overloading the outputs? But anyhow, I will tell him about the filter caps, ect, and see what he thinks. You at least have given me an idea about what could be wrong, and the price range is a bit steep for a high school student. :D Thanks, though, you've been a great help.