My PMP5000 shuts down the mains frequently.

SOURCE: I have a PMP5000, used 5 times now. Last gig I

Cease using it immediately and get it serviced. There are failure modes of this that can do serious damage that requires a lot of work to repair.

If the temp sensors shut it down, it will restore if cooled off... If that doesn't happen service is required.

If just one side of the speakers went out I know exactly what has happened as I have repaired three of these all with same problem. If both sides are down and the rest seems to work, that is an uncommon failure

The cooling fan is throttled as needed and runs only when heat sinks get to a certain temp.

SOURCE: you seem to be the

The MON faders ONLY control the output to the MON L and MON R jacks, NOT the split use of MAIN/MON outputs. You MIGHT try varying the MONO fader and see if it varies the MON part of the split output.
Best to use the unit as MAIN L and R to main speakers and use a stereo amp or POWERED monitors driven from the MON L and R jacks. With this, the MON faders will control your monitors as you would like them to.
ALSO make sure ALL equipment connected together is powered from teh same recepacle power system. Powering interconnected equipment from receptacles at opposite ends of the room is asking for damage due to ground bounce and faults.
PLEASE read my tip on here about a HAZARD of speaker polarity if you use Speakon to 1/4 inch cables.

SOURCE: I have a Behringer Pmp5000. I have lost all power

If the input are working, the power supply is still alive.CEASE using it immediately before you increase the damage.
The amp module in this has failed. The usual cause is an insulation breakdown of the circuit board in the amp followed by failures of the switching transistors in the class D amp. It is for all intents and purpose fatal to the amp module. I have repaired several of these amp modules and it requires a lot of time and skill. You are better replacing the module economically as they are $160 for the module. The real problem is the replacements are VERY scarce and the only source seems to be FullCompass.com. The module is an HCA2400.
There are NO internal fuses. When replacing the power amp module, make sure to dischrge the big 70 volt filter caps before plugging the new amp or you will do "welding" when you touch the contacts to the plug.
Also PLEASE read my tip on Fixya about these PMP mixers and a hazard when usuing 1/4 inch plug adapters regarding channel A.

SOURCE: Just bought a used Eurocom

Oh my... yes I know what happened. Since it won't come on, the power supply has failed. It takes out the SPS1000 supply and one or two of the IGBT switching transistors on it and often the precharge resistors and the regulator chip and the driver transistors and a speedup diode... in all about $30 of parts and lots of work restoring. DO NOT replace the fuse without repairing or it can blow more parts. ALSO the cause of the supply failure can be one of two things I have seen: A shorted capacitor... either electrolytic or a ceramic surface mount (I have seen both) AND possibly a failure of one of the two amps on the HCA2400 amplifier module. That repair can be miserable as it often is caused by an arc-over between layers of the circuit board. If you have warranty on this unit best to exercise it immediately. The repair parts cost will be between $30 and $50 wholesale. The labor is hours of work. I would NOT recommend this unit to be used for electronic drums at high levels.
Also read about the hazard regarding use of Speakon to 1/4 inch adapters or cables I posted as a tip on Fixya for PMP units. Essentially the A channel output SLEEVE, not the tip of the 1/4 inch adapter speaker cable is the HOT. Inadvertently ground the sleeve by any means and goodbye channel A of the amp. They don't tell you this in the manual.

SOURCE: We have a Europower pmp5000.

Very strange behavior. Knowing the electronics within the unit, I see no reason that moving the main volume could restore operation. i tend to think that is a coincidence. Possibility the vibration of moving the control caused it to operate again. Do read the tip about PMP mixers I posted on Fixya about the hazard of channel A output if you use Speakon to 1/4 inch cables or adapters. If this happens again, try headphones and see if the signal still comes through them. There is an electronic fuse that can kill output IF the output current gets too high, but for that one you have toturn power off for some time for it to reset. Since you did not turn power off per your posting, that possibility is ruled out. Normally the sliders will NOT fail midstream and would be restored with any slight movement.