NO SOUND FROM THE MIXER?
FIND WHERE THE SIGNAL STOPS

A DJ mixer goes quiet in four different places, and which one it is decides everything you do next. Your music is almost never the problem here. Signal routing is.

• One channel, the others fine. A deck you cannot hear on a mixer that is otherwise alive. You still have a working channel to play on, so nothing is at risk while you look.
• Everything silent. Nothing leaving the mixer at all. This is the only one of the four where the room has no music in it, and it is the one to treat as urgent.
• Nothing in the headphones. The room is playing and you cannot pre-listen. The crowd cannot tell, and you can fix it between tracks.
• Sound, but wrong. Thin, quiet, distorted or coming from one side. A different fault with a different list, at the bottom of this page.

Answering that question first is what stops the classic waste of a set: a DJ chasing cables behind the desk for a channel that was assigned to the wrong side of a crossfader.

Changing the wrong thing while the room is still playing is how a fixable fault becomes an expensive one, so these rules sit above the fixes rather than below them.

• Master fader down before you touch any connector. Back up after. That covers reseating a master cable, moving your source to another channel and swapping a suspect lead. Plugging into a live PA sends a full-level thump through it, and drivers die that way.
• Anything patched in behind the mixer is the venue's. A processor sitting between the master output and the amplifiers can silence a room, and pulling it is not your call. Ask first.
• The amplifiers are a question, not a check. In most venues the rack is not in the booth at all, so whether the amps are powered is something you ask someone, not something you go and look at.

Everything else on this page is a control on the mixer surface in front of you, and every one of those is yours to move.

A single dead channel on a mixer whose other channels play is a setting far more often than a fault, and there are three places it hides. Work down the strip.

The crossfader first. Sweep it right away from your channel and back, then find the crossfader ASSIGN switch for that channel, the one marked A / B / THRU, and set it to THRU. Nothing costs less and nothing catches more DJs.

No ASSIGN switch anywhere on the surface? Some mixers do not have a crossfader at all: the DJM-V10-LF, the DJM-V5 and rotary mixers are the ones you meet. On those, every channel already behaves as THRU, so this is not your fault and you move on.

Then the strip itself. TRIM or GAIN back to 12 o'clock. COLOR FX off, and the FILTER knob back to 12 o'clock. A filter left swept hard to one end by whoever played before you mutes a channel while every other control on it looks perfectly normal.

Then the input. At the top of the channel strip is the source selector, something like USB / DIGITAL / LINE / PHONO / RETURN, and it has to be pointing at wherever your music actually arrives. The position worth knowing about is RETURN: that is the mixer's own effects loop, not your deck, and a channel sitting on it with nothing coming back is silent and looks completely ordinary. AlphaTheta document it on the DJM-A9 as the position that selects the effect sound from external equipment, and the DJM-750MK2 carries the same idea as RETURN AUX on each channel input switch.

Still nothing after all three? Master fader down, move your source over to a channel you know works, master back up.

When all the channels on a mixer die at once, the master section is where the signal stops, and the send and return loop is the part of it that nobody thinks to look at.

Levels first. MASTER up to 12 o'clock, and BOOTH with it, so you can hear the difference between a fixed mixer and a fixed room.

Then the loop. Find SEND / RETURN and switch it off. On a DJM-900NXS2 or a DJM-750MK2 there is a RETURN TYPE switch beside it: set that to AUX. Left on INSERT, the mixer puts whatever comes back from the outboard unit in place of your sound, so if nothing comes back you get silence with every fader up and every meter needle where you expect it. On a DJM-A9 the same loop lives under MULTI I/O. A DJM has no insert jack of its own; what it has is this loop, and it can be aimed at a single channel or at the master.

An Allen & Heath desk does it with a real insert, and it is the best documented version of this trap on the site. On the Xone:96, a jack terminated into MASTER INSERT RETURN breaks the through connection to the master bus, and Allen & Heath state plainly that if the outboard device is off or not passing audio there is then no signal on the master bus or the meters. Pull the jack and the through connection restores itself. The Xone:24 ships with shorting plugs in those sockets for exactly this reason, and if they have walked off while the MASTER INSERT button is lit with nothing patched, the master output is dead while every other light on the desk looks normal.

Then look behind. Venues patch processors between the mixer's master output and the amplifiers, and one that is powered down or sitting in a bypass that does not pass audio silences a room just as thoroughly. That box is almost certainly the venue's, so it is a question rather than a fix: is there anything in the master path, and if it is dead can you go straight out of the master?

The master meters on a mixer are a diagnosis in their own right, and the Xone:96 is the model this site has documented both halves of it on.

• Dead meters, silent room. The bus itself has been broken, which points at the insert return rather than at anything downstream of the mixer. Everything on the top panel can look correct while this is true.
• Healthy meters, silent room. The signal is reaching the bus and losing its way after it. On a Xone:96 that is a documented behaviour rather than a fault: Allen & Heath state that adjusting MASTER 1 and MASTER 2 does not affect the LR MIX meter display, so a master level sitting at zero gives you a completely normal meter picture and a silent PA. Check the levels, and check which of the two master outputs the house system is actually plugged into.
• Booth alive, master dead. The booth feed is separate on plenty of desks. Allen & Heath describe the Xone:43 booth output as a line level feed to the DJ monitor that is not affected by the master fader or the cue system, so hearing yourself in the booth tells you nothing about what the room is getting.

This is also why the meters are worth naming out loud when you go and find someone. "The master is up and the meters are moving" is a sentence a house tech can act on immediately; "there is no sound" is one they have to come and investigate from scratch.

Past the master output the signal is in cables and in the venue's system, and the mixer has stopped being the suspect. Master fader down before any of this, back up after.

• Reseat the master output cables at both ends. Both, not one: a half-seated plug at the far end looks identical to a good one from the booth.
• Move the master pair onto the booth output if the connectors fit. On most DJMs the booth out is a pair of quarter inch jacks, so house XLR cables need adapters, which is worth knowing before you need it rather than while a room waits.
• Amplifiers powered? Ask, do not go looking. See the rules above.

When it is genuinely past your gear, hand it over with the evidence attached: the mixer master is up, the master meters are moving, and there is nothing after the booth output. Tell them what you have already been through as well, because it is a real list by this point: channel, crossfader assign, input select, trim, master level, the mixer's send and return, and the output cables at the mixer end. Once the silence starts after the booth output, it stopped being yours to answer for. Keep the set cued and be ready to go the moment it comes back.

Silence in the headphones with the room still playing is the mixer's cue path, and it is the one no-sound fault a crowd cannot hear. Take it in that order: the cue controls before the socket.

• Headphone MIX all the way to CUE, not sitting over towards MASTER.
• Headphone LEVEL up to about halfway.
• Then the socket: a plug that is not all the way home is the classic, the second headphone socket if the mixer has one, an adapter screwed down properly, or somebody else's headphones to rule out yours.

If none of that brings it back, you mix the set without cue. Long blends, tracks you know well, and the waveforms on screen doing the work your ears were doing. The crowd has no way of hearing that anything changed, and nobody asks. That is an outcome, not a failure.

Sound that arrives thin, quiet or on one side only is a different fault from a silent mixer, and most of the time it is the settings the DJ before you left in the desk.

Zero the strip, which takes about five seconds. Sweep the channel EQ knobs back to 12 o'clock: hard left is not technically off, but on a DJM-900NXS2 in EQ mode it cuts to minus 26 dB, which sounds like off from where you are standing. Then find the isolator and set it flat. On the 900NXS2 that is the EQ CURVE switch; the DJM-V10 carries a separate three-band master isolator.

Thin in the booth but right on the floor is the monitor path, not your signal. A DJM-A9 or a DJM-V10 has its own booth EQ, HI and LOW, sitting on the monitor feed only. A DJM-900NXS2 has no booth EQ at all, just the BOOTH MONITOR control. Either way the floor never heard a problem, which is worth knowing before you start moving things that the floor can hear.

Then the physical layer. Reseat every jack in the path, because half-inserted is what produces sound from one side only. Set TRIM so the channel meter peaks orange and never red. Swap the suspect cable: cables fail far more often than mixers do.

Still wrong? Isolate it in three moves. Move your source to another channel, and if that fixes it the fault is the channel you left. Try the other output, booth against master, and if that fixes it the fault is the output and the house needs to know. Wrong everywhere is a source fault, so change the cable and change the device.

None of the moves on this page are worth a silent room, so the last thing a mixer owes you is a way to keep playing while it stays broken. Stop diagnosing and get noise out of the speakers.

• Move everything onto a channel you know works, even if it means sharing one.
• Ask the DJ before or after you. They have played this desk and they know its quirks.
• Ask the sound tech for any spare input at all. A phone into a line channel counts.
• Keep the room going on whatever still plays. One deck does not let you mix, so this buys time rather than a set, and time is what you need.

If you want that walked through decision by decision while it is happening, the guided rescue asks one question at a time and remembers where you are.