My powered mixer Behringer is buzzing

Hello Doug, obviously for what you are saying, you would have a problem in the effects processor of your Behringer, I suggest you use an external processor to corroborate that the problem is not in the shipping bar, or in the allocation of returns
If you have technical knowledge, disarm the mixer and control the internal connections of the effects processor, see if there are no loose solders
I sent you the link to download the circuits of your PMP5000
If you do not find the origin of the fault, look for a specialized technical service
I hope you can solve the problem
Greetings Franco Dosil

Hola Doug, evidentemente por lo que comentas, tendr?as un problema en el procesador de efectos de tu Behringer, te sugiero que utilices un procesador externo para corroborar que el problema no esta en la barra de env?os, ni en la asignaci?n de retornos
Si tienes conocimientos t?cnicos, desarma el mixer y controla las conexiones internad del procesador de efectos, observa si no tiene soldaduras flojas
Te env?o el link para descargar los circuitos de tu PMP5000
Sino encuentras el origen de la falla, busca un servicio t?cnico especializado
Espero puedas resolver el problema
Saludos Franco Dosil

https://www.electronica-pt.com/esquema/audio/behringer-audio/behringer-europower-pmh5000-rev-d-15967

If it goes back to normal after you shut it off and letting it sit for a bit, it's related to heat buildup. If that's the case, it's either a component failing or a cold solder joint that opens when a part expads/contracts from itr's contact point. Either way, you needto take it to the repair shop.

First read the instructions they contain some amazing information. I can not help you because I have no idea of what you want to know.

First read the instructions they contain some amazing information. The setup is a subjective function and dependent on what equipment you are connecting to it.

Can you elaborate a bit more about what you mean by "turning off?" What are you doing up until that point? Does it do it at certain times, etc.?

If it buzzes when you have no inputs AND no output leads connected, there is a problem with the power supply... HOWEVER if you have used UNBALANCED output cables instead of the REQUIRED TRS BALANCED output cables, it is possible the noise is being driven backwards and that is what you are hearing. Note that at full gains, there often is a tiny bit of noise, usually hiss. Also make sure the supply is powered from the SAME receptacle as the equipment this drives such as an amp or powered speakers.

Check the 5 volts to the FX unit, If the voltage is low, the FX processor will keep reseting generating clicks, In a different product, the 5 volt filter cap was degraded and voltage dipped down to 4.5 volts causing resets.

Here you go:

This is a wild educated guess.

I repaired a Behringer guitar amp that had a DSP effects in it (BX1200 I believe).

The effects were on a seperate board and the board had its own 5 volt power supply. The filter capacitor for the 5 volt power on the board was UNDERSIZED and it had degraded causing the 5 volts to drop out of regulation, dipping to 4 volts. This caused the DSP effects to fail.

YOUR device MAY use the same DSP OR design.

Check the 5 volt power with an OSCILLOSCOPE to look for dips below the 5 volt operating point that occur at 120 HZ.