Behringer Europower PMP2000 mixer

[Techknowman]

I already know the answer but Behringer PMP2000 schematic?
I know no one that is a service center can send a schematic. but I need one to understand two units issues. I have 2 of these units in my shop.

1 Hums when you turn it on for a second then is quiet. sound is ok but customer complained of unit squealing loud at times.

The other unit has a dead output channel.

How do you become a legit service center to get Behringer schematics and parts if needed? I hate not really being able to give my best on these units but with no info it leaves the unit in one of three states.

Tell customer you can't help them, have to take it to a berginger service center, If one is around.

If they have just brought it from said place. Tell customer of issues with said company and its support and that cost of repair will probably be more than the value of the unit because you will have to work blind, and not recommend said company for next purchase.

Try to do the best you can with info that is obtainable. (Thankfully the Class D is somewhat simple just mostly SMD/SMT)

Seems like once a month I get one of these Class D nightmares needing help. To me, it just seems like they are trying to pack way to much wattage output in small component packages.
Not just Behringer, Genz Benz too.


IMO / BTW I would not buy a Behrginger unit with any of the PMP modules in it for myself and the local bands I service have been moving away from them as well. they are using Mackie and QSC as well as Peavey and Galien Kruger.

[Enzo]

What amp is in that one, the HCA2400 maybe?

Isolate the problem, use the patch jacks, preamp or poweramp?, and when a channel is dead, don;t overlook the patch jacks themselves.

I can't post it, but more and more of their schematics are showing up online, go googling. And do some search here, I think a few may have been linked from here.

How do you get connected? Like any other company, you contact them and ask if they are taking applications for service center status. I believe they are not, but can't hurt to ask.

ANy company that is looking for service centers wants to provide service to their customers. SO don't ask them and mention wanting schematics. Tell them you have a growing number of their product owners coming to you for service under warranty, and you must turn them away. And there are no nearby serviuce centers. That way you are filling THEIR need, not them filling yours, right? Like applying for a job. Of course, you need to look up where the nearest centers ARE. If there is one across town, sorry. If it is two states away, you look more attractive. Are there any local dealers selling Behr? Got a relationship? I do work for several dealers. I call a manufacturer and say Dealer XXX has asked me to become one of your service centers.


COnsidering the incredible volume of Behr amps out there, I am not so sure their failure rate is higher than anyone else's. The more a product is sold, the more of them you will see.

[Techknowman]

Im not sure which one it is.
Its got the power supply integrated with it and 2 square vents routed in the board.
On the one with the startup hum, I haven't been able to get it to squeal like the customer described.
The other I haven't put on my bench yet.
Thanks, I'll look around.

[Enzo]

The amp model will be silk screened on the board.

A common source of squealing in any amp is gain plus a loss of ground at an input. That can be the ground connection to a jack, but can easily be a bad cord they are using.

[Techknowman]

It may be silk screened on the board but it isn't in an easy to see place.
May have to disassemble the unit to find the number. It probably under the can the fan mounts on or the back of the board mounted against the back chassis.
Yea I figured that it could have been the input jack or one of there connectors /cables.
I did find a bit of a cold joint on the switch used for LEFT/RIGHT / Bridge mode

[Enzo]

Fix one at a time, or do two threads, or at least call them unit A and unit B, or Fred and Ethel even. Otherwise it is confusing just what "it" we might have in mind.

Fred
An amp like that that hums then goes silent but still works (right?) sounds to me like possible power rail imbalance at power up, scope the rails. And use the patch jacks to determine if the moment of hum is from the power amp or the mixer. And if it is just a second or two, it may just be like a turn-on thump that got stretched out a little.

Ethel
One dead speaker out? Use the patch jacks to determine if the power amp is it or if one side is not leaving the mixer portion. I haven't had to resolder them, but I have had to spray some cleaner in the stereo/mono/bridge/main-mon/power amp assign switches. And if that one has a "speaker equalization" on/off or something like it, clean that too. And I have to say that when the mixer loses a left or right, more often than the other things is a bad main fader.

[Techknowman]

Fred seems fine now after cleaning and resoldering the stereo/mono/bridge/main-mon/power amp assign switch. Ran it hard on my dummy load and it worked great, so i'm calling it good. I will recomend that the user check his cables and such. BTW it looks like its amp module is a P2502 as well, just not silked like Ethel is. http://www.fullcompass.com/product/368223.html

Now to Ethel. She is very ill. She is actually a PMX2000. Amp module is P2502
Powers up with a thump on both channels but not bad.
Main level meter is pegged. Moniter level is at half. They stay this way no matter what.
One channel works fine on all inputs. volume, tones and EQ controls works but other channel is dead.
Switching stereo/mono/bridge/main-mon/power amp assign switch makes no difference.
Turning off power, dead channel pops kind of loud.
I pulled the mixer section so I could look at the 12 pin ribbon cable that goes between the amp and mixer. (12P)
I'm going to ring them out since without a schematic thats all I can do without it turning into a research, reverse enginnering project.
So maybe some pointers?

I want to thank you for the help.
If I sounded a little grumpy before, its just that it is very fustrating to me not to be able to get information for a device.
I'm not an expert, but i'm not a novice ether.
By my documentation this is the 51st amp I have worked on in 8 months, and this is just my side hobby, extra $ job.
I have only turned 2 away unrepaired because they were units you could buy new for $150 and they were pretty badly toasted and it just wasn't realistic.
If your curious check out my real jobs website. www.trottercontrols.com. I have designed, built and service over 85% of what we sell there.

[Techknowman]

UPDATE!
I finally found a schematic for the P2502 used in the PMX2000.
I'm confused now! the schematic I have shows the P2502 as a Class A/B with NPN and PNP drivers and outputs.
So is the PMP2000 unit a Class D with a different part# ?

[Techknowman]

This is photos of the 2 different units.
Amp sections.

PMX2000 with P2502
Behringer_P2502-1.pdf

PMP2000 with ?

[Enzo]

PMP2000 is a newer version of the older PMH2000 (That looks like X but is an H). SOmeone around here figured out that the schematic, though not maybe all the part numbers and such were about identical to some Peavey mixer amp, I wanna say XR684 maybe? If you are googling, try PMH instead of PMX, can;t hurt.

The PMH2000 2502 amp had the C5200/A1943 outputs. As far as I know the PMP2000 uses the same amp, 5200/1943, no MOSFETs. Certainly your two photos look like the same amp. We can't see under your fan vaults here.


Make sure the problem is in the amp or not. Feed teh PA in jacks, still bad? Between the PA in jacks and the 2502 inputs is IC16, the speaker EQ staqge, which you can switch out from the panel. But the inputs to it are on the bus either way, and they are protected Peavey-like with pairs of diodes to the 15v rails. D3-6. A shorted diode puts 15VDC on an output bus from the mixer. And DC would explain the pegged meter. How are the MAIN L&R jack signals?

[Techknowman]

Thanks ENZO!
The XR684 search panned out. It does look like its the right mixer unit.
Have to dig in for sure when I get back home. Should be out of the dark and into the light now!

[Techknowman]

The XR684 is close but its not the same. Very glaring differences. Reference designators don't match ect.
However I did find one of the diodes on the channel inputs shorted to the -15V rail. Replaced it so now I have sound from both channels and no pegged out meters.
But the system pops really bad when the EQ switchs are pressed in or released.
looking at the common of the switch there is about +3.5V referenced to ground on both left and right channels.

[Enzo]

The schematics won't be the same, but the circuits are very close, so it becomes a matter of trying to use the drawing to direct your efforts. Most of the parts seem to have theur parallels.


Don't know where those volts come from, lift those four diodes and see if one is leaking. Check the outputs of IC16, are they offset?

Toggle that EQ switch. WHich leg is bringing that 3v? Either it is on the common and coming back from the power amp, or it is getting to the common through one leg of the switch, which would mean either from the IC or from the mixer.

[Techknowman]

Its coming in the common on both EQ switchs.
I replaced all the diodes just to be sure. While I was looking around I found Cap debris. C59 on the mixer board blew its guts out.
I replaced it.
its looking like someone jacked in a power amp into the wrong inputs?
The mixer board is a PMX2000 PCB 317010 Rev F /01
And wouldn't you know while I was messing around I broke VR39. Grrrr Want to sell me one?

[Enzo]

Or something not properly grounded.

The common terminals of those EQ bypass switches go directly to the 12 wire ribbon to the PA.. Ober there3, one sees a resistor and blocking cap, the other channell does wire to an op amp. I see noting that would put 3v on both. Good luck.

I don't have parts to sell. John Frondelli here sells them, and Full COmpass does as well.