Behringer Europower PMP980S overheating

[Mordred]

Hello all,

Nice place you have here. I just registered so I could ask about my PMP980S overheating...

I was using the PA with my amp and I lost output. When I touched the back of the unit, it was very hot and had a peculiar smell. I immediately turned it off.

Gear used:
PMP980S w/ Speakon > 1/4" cable
Peavey 12" neo Speakers
Behringer Ultravoice XM8500 Mic w/Shure (Monster) XLR

Next day, I turned it on to see if I could do any kind of troubleshooting, and I noticed there was a loose ground cable on one of my speakon speaker cables (Speakon > 1/4 inch speaker connector) on the 1/4 side. I replaced both cable connectors, verified Speakon side and found no issues. Checked my XLR cables, external instrument lines, all are working properly. Finally, grabbed one mic and hooked it all up. The amp works... I can hear all, works like it always did... and after a while, it starts losing power and eventually dies down. There's input because all the lights remain on, and when I use the mic, I can see the dB meter lights going off and all, but no output. Turn it off, wait for it to cool off, turned it back on, worked fine for a while. Then it gets hot and starts to die down again, just like a computer would when the processor overheats.

My line of work is Information Systems so I have a fair amount of RTFM and troubleshooting experience... so I am trying to find out if there is a cooling system in there that may have failed, like a fan... but I can't find any instructions on how to open the unit itself to verify fan/cooling functionality. It seems this may be the problem because I do not hear a fan whir in there at all.

Thank you all for your help.

[Jazz P Bass]

These mixers are an absolute nightmare to take apart!

And now, the bad news:

The power supply is switch mode.

The amplifiers are Class D.

There are a ton & a half of surface mount components inside.

After working on a few of these, I now pass on any & all repairs of these units.

[Mordred]

Hi, Thank you VERY MUCH for your help!

The unit was very easy to open, at least the rear panel. I removed the 7 bigger screws (heads were protruding from the back and as a general rule, those are the one that generally hold housings together), and took a look inside. I immediately noticed the 80mm computer fan attached to the back of the preamp, over a metal cover housing the heat sinks and components inside. I had to remove the housing as the screws are mounted from the inside out, and that was the most time-consuming task of them all. Removed the preamp from the back panel, removed the metal housing from the preamp, removed the fan and replaced it with another 80mm fan. Put it all together and it's been working since.

I could tell the fan was gone because, aside from it not spinning (I tested it anyway), it was full of black grease and whatever it is they have inside, looked like black sticky dust.

It's a good thing that this was an easy fix! I can imagine how much more expensive it could have been. It's a GREAT thing you guys are here to help out, and I thank you again for your quick response.

[Jazz P Bass]

Great!

Maybe we could use this thread as a 'sticky' on how to take these apart.