Sounds like the output cable from the 802 is not correctly pinned to your input on the computer. Fred is on the right track but you may need to take it a bit further.
It may also be helpful to use a Pro USB audio interface such as the Digigram UAX220v2 (line level version).
If you wish to use the computer's on board sound card consider an IHF/Pro interface that converts balanced audio to unbalanced , and the proper cables. Two 3-wire balanced 1/4-inch from the 802 to the left and right inputs of the interface (XLR Male), then RCA (Red and White) to a 1/8-inch TRS Plug cable onto the the computers audio input.
Henry Engineering's Matchbox HD comes to mind.
Good Luck.
It can be a number of things. Bad ground, excess gain, excess number of mixer channels with no inputs, Make sure the mixer inputs you are going to use are the only ones that are up. Power supply noise- flourescent lighting noise, Clamp on ferrites on the power cords of everything can help reduce this. You can sometimes track the offending source with a battery powered AM/MW radio. It can also be caused by going from a balanced output to an unbalanced input with some impedance differences.
There are a variety of ways to accomplish this, but the two most common ways are:
Purchase a BEHRINGER USB interface -- like a U-CONTROL UCA222. This will allow you to use the USB port for your sound In/Out. This will also require RCA cables to connect from mixer to UCA222 unit.
Or...purchase a dedicated sound card (preferred) like an M-Audio Audiophile 2496 that can be installed in your computer (not for laptop). You will also need I/O RCA cables to connect.
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.
Phantom should ONLY be on if using CONDENSER mics or a DI box requiring phantom power... yours should be OFF. cables should be correct. The 2 Trk to mix button should be down.
You will need an oscilloscope and a good grounding in electronic servicing to attempt a repair.
But, check the signal routing. Refer to the user manual.
It sounds like you're experiencing a couple of issues with your Behringer Xenyx 1204FX mixer. Let's address each of these problems separately:
DSP Display Not Illuminating: The fact that the DSP display works when you press down and turn the knob suggests that the issue might be related to the display itself or its connection. Here are a few steps you can take to troubleshoot the problem:
Check Power Source: Ensure that the mixer is receiving proper power and is turned on. Sometimes display issues can be caused by power-related problems.
Connection: Make sure the ribbon cable or connector that connects the display to the circuit board is properly seated. A loose connection could be causing the display to not illuminate.
Faulty Display: If none of the above steps work, there might be a problem with the display itself. You may need to contact Behringer support or a professional technician to get the display repaired or replaced.
AUX 1 Send Not Working: If the AUX 1 send is not working as expected, there could be several reasons for this:
Routing Settings: Make sure that the AUX 1 send is properly routed to the desired destination. Check the routing options on the mixer to ensure that the signal is being sent to the correct output or destination.
Level Controls: Verify that the level controls for AUX 1 are set correctly. Make sure that the AUX 1 knob for the specific channel you're working with is turned up.
Effects/Processing: If you're trying to send a signal with effects applied, check if the effects are set up correctly. Sometimes, an incorrect effect or routing setting can affect the AUX send.
Cable and Connections: Ensure that the cables connecting the AUX 1 send to external devices (such as monitors or effects units) are functioning properly and securely connected.
AUX Master Level: Confirm that the AUX 1 master level (usually located on the main output section of the mixer) is turned up to an appropriate level.
If you've gone through these troubleshooting steps and the issues still persist, it might be a good idea to consult the user manual for your Behringer Xenyx 1204FX mixer for further guidance. If the problems continue, you may need to reach out to Behringer support or consider seeking assistance from a professional audio technician or repair service.
Hello Geoff, try using an external processor and check that it works well, if so, the problem is that you have the Jack connectors of Effect sending and those of Return of Effects, dirty
Apply a couple of drops of oil, type WD40, to a Plug connector and insert and remove them repeatedly in each connector Jack for sending and returning effects
I hope you can solve the problem, comment the results
Greetings Franco Dosil
Hola Geoff, prueba usando un procesador externo y comprueba que funcione bien, si es asi, el problema es que tienes los conectores Jack de envio de Efecto y los de Retorno de Efectos, sucios
Aplicale en un conector Plug un par de gotas de aceite, tipo WD40 y entralos y sacalos repetidamente en cada conector Jack de envio y retorno de efectos
Espero puedas solucionar el problema, comenta los resultados
Saludos Franco Dosil
https://media.music-group.com/media/PLM/data/docs/P0A8M/PMP1680S_PMP980S_PMP960M_M_EN.pdfhttps://c3.zzounds.com/media/PMP1680S_P0A8M_OI_EN_ES_FR-df44b2314272dfc61a7cabe5bb88ecce.pdf
Check all the wiring connections on the speaker. Check the plug in points for the cables are not loose in the body of the speaker or the connector plugs themselves are not loose in the actual plug sockets.
Next you will need to get inside the speaker body to check the connections and soldered joints. Take a good look at the back of the cable plug sockets and to the back of the actual speaker cone connections. Check each wire at Both ends for damage. No sound at all suggests the issue might be at the 'Input' where the cable plugs into the back of the speaker body.
If the right input on your Behringer Ultracoustic ACX1800 CD is not working, it could be due to a number of reasons, including:
A faulty cable or connection: The problem could be as simple as a loose or damaged cable. Try swapping out the cable with a known working cable or check the connection to ensure that it is secure.
A blown fuse: The ACX1800 CD has a built-in fuse that protects the internal components from power surges or other electrical issues. Check the fuse to make sure it is not blown and replace it if necessary.
A damaged preamp or amplifier circuit: If the problem is not with the cable or fuse, it could be due to a damaged preamp or amplifier circuit. This can be caused by a number of factors, such as overheating, power surges, or other electrical issues. In this case, you may need to take the ACX1800 CD to a professional repair technician to diagnose and fix the problem.
A faulty right channel input jack: It is also possible that the right channel input jack itself is faulty. This can be caused by wear and tear over time or physical damage. In this case, you may need to replace the input jack or have it repaired by a professional technician.
Based on my research, the Yamaha PMH5000 mixer features two 1/4-inch "insert" jacks for connecting external effects processors, such as compressors or equalizers, to individual channels. These jacks are not intended for connecting external power amps.
However, the PMH5000 does have two "main out" jacks that can be used to send the mixed audio signal to external power amps. These are typically located on the back of the mixer and may be labeled as "L/R" or "Main Out."
When you connect an external power amp to the main out jacks, the signal is sent directly to the power amp and is not routed through the internal power amps of the mixer. The external power amp then amplifies the signal and sends it to the speakers.
It is important to note that when using external power amps, you should adjust the volume levels carefully to avoid damaging the speakers or the power amp.