HELP!!! Coliseum 300 just crapped out

[EarthRumbles]

Our coli 300 just stopped outputting all of a sudden at practice. I have no idea why, its not buzzing or anything like a grounding issue its not putting out anything all you can here is the hum of the amp itself, guessing a fan. Any ideas, or places to start trouble shooting. Please help, thank you.

[mckinnon audio]

  Hi there,disconnect the AC going to the amp and check all fuses and/or breakers to see if any have blown or tripped.Fuses have been known to fail,same idea as a light bulb blowing out,the filament gets thin and eventually fails.Of course there could also be other problems such as power supply or output stage.If you find any blown fuses,just replace them the one time,if they blow again,get it to a tech before you damage it any more.Good luck,Mel.

[EarthRumbles]

Ok so it died that night, then the next day it worked fine, granted I only tested it and didnt put it through a few hours of use. My question now is, what happened? Are the coli 300's known to overheat or anything that might cause it to just need to cool down? If so is there anything I can do? I checked quickly online and there seems to be some confusion as to whether there is a cooling fan in the hear or not, can anyone actually confirm this and if there is a fan which Im thinking there probably is, would replacing the fan possibly help fix the issue? Thanks for the help.

[loudthud]

When it stops working, plug a guitar or bass into the Power Amp input. It should make some sound if the power amp is still working.

The Power Amp Input jack and any of the "Return" jacks have contacts internally that disconnect the signal if a plug is inserted. These contacts can become intermittent if not used for years or if the solder connections to the circuit board break. Insert and remove a cable several times to clean the contacts. Try some contact cleaner like De-Oxit.

[EarthRumbles]

Ive checked the jacks and they all should be good and I plugged into the power amp in and still nothing. The LED for the input is getting signal, LED for the compressor is getting signal and the LED for the Power amp is lighting up as well. I tried to different cabs and a few different cables and bass's. Any ideas?

[mckinnon audio]

   Hi there,sounds like you have signal to the input stage of the power amp,but it's not going through the output stage.To make sure the preamp is ok,take a line from your preamp out and make sure signal is there.It could be something as simple as an internal fuse or fuselink.If you know how to use a volt meter it's time to start taking some voltage measurements,etc.,if you don't,it might be time to take it to a tech. Good luck,Mel.