Behringer PMH3000 power supply

[davepoole]

I have a Behringer PMH3000 powered mixer with a faulty power supply. The psu type is SPS600. There are four blown surface mount resistors on the reverse side of the board- R65, R66 and R56,R57.

Can anyone help with either a schematic of this power supply or the values for these resistors.

Thanks in anticipation.
Dave

[Enzo]

Part is called out as E047, which to me looks like 0.047 ohm

[davepoole]

Hi Enzo.

I could see "R??7" on the burnt out resistors and thought it must be R047 so thanks for the confirmation.

Dave

[Enzo]

Yes, they use E instead of R on their resistors in the schematics for some reason.

[bassman83]

Behringer pmh3000 power problems

I have a pmh3000 and my problem is when you plug it in and push the power button the board lites up and immediately shuts down. I was wondering if this has happened to anyone or someone could give me some feedback on what they think the problem is. Any information is greatly appreciated.

[Enzo]

Probably a blow power amp. The switching power supply comes on for a moment, recognizes the excefss current draw from the failed power amp module, then shuts down.

I forget, does that one have two power amp modules, or one stereo power amp module? Either way, if there are two, then disconnect one at a time and see if either makes a difference when gone. If it is a stereo, then disconnect the power supply from it. Don't forget to disconnect the smaller wires. The main power is heavy wires on a three or four wire connector. There is also a low voltage supply connection on a small connector with skinny wires, so unplug that as well.

If one of the power amps is shot, then we might fix it. If disconnecting them makes no difference, then there is a short on the mixer board somewhere.

[bassman83]

I actually took it to a repairman who told me he thought it was a bad power supply board i believe. He also said if he got the supply board going he wasn't sure if the power amp side of the mixer would work. He isn't a authorized behringer repairman but he does all the repair work at local store. He called an behringer repairman to see if he could get the schematics on the mixer but never recieved the follow up call or schematics. He said if he had the schematics he could probably fix with no problem but he couldn't get them from behringer or the authorized repairman. So as of now i'm still with a nonworking mixer.

[Enzo]

Behringer won't allow us to share schemastics, but if you took it to a Behringer repair facility, they should be able to repair it.

Have your guy try what I suggested in post #6. I am not sure how he would determine the difference between a faulty powr supply and one that had shut itself down.

[bassman83]

Thanks Enzo for the information. I will have him check that out.

[Asalt]

Another Berhringer PMH3000

I also have a PMH3000 with a Bad Power Supply (SPS600). I found at least two components that are charred. I intend to replace them, and then test the supply by itself before connecting the power amp or mixer. Is it OK to test the +/-70V power supply unloaded or should I load each side with say a 1K-ohm 10-watt resistor?

Any other advice on where to dig into this power supply would be appreciated. Or any advice on how to make the supply itself more rugged. It looks like others have had problems with these power supplies.

[Gtr_tech]

Behringer won't allow us to share schemastics, but if you took it to a Behringer repair facility, they should be able to repair it.

Nice behavior from a company who made thier fortune from copying other ppl's products. Its been a long time since that was a secret.....

They's the modern day Earth Sound Research!

[Enzo]

The power supply should work without a load. But I'd recommend pulling off both high and low voltage connections - in other words, don't disconnect the +/-70 but leave the +/-15

[Asalt]

What's the circuit behind the speaker connectors

I've isolated a problem to one channel on the circuit board between the power amps and the speaker connectors on PMH3000. Each channel on the circuit board contains a triac and a bilateral switch. Is this some type of protection circuit?

[Enzo]

It is the same idea Peavey uses on most of its SS power amps. Yes, there is a triac crowbar across each output. If the triac is shorted, remove it and see if hte rest of hte amp still works. Usually the triacs come on when sensing DC and then they short out protecting your speakers.

[Almis]

I have a Behringer PMH3000 powered mixer with a faulty power supply. The psu type is SPS600. There are four blown surface mount resistors on the reverse side of the board- R65, R66 and R56,R57.

Can anyone help with either a schematic of this power supply or the values for these resistors.

Thanks in anticipation.
Dave

resistors values is 0.047ohm 1w