Sound outputs not working on mixer

[ciarancussen]

I have a marlin 10400 and the left outputs don’t work at all (no audio or power). I’m not too sure what it could be. I’ve tried all the other inputs and turned off phantom power, still no change. Any help would mean a lothttps://youtu.be/8hFd3mji_a8

[Drew Stephenson]

Assuming it's not something as simple as the pan pot being all the way over one side, which I assume was the first thing you checked, then it looks as though that channel has gone.
The question is where. Does it have a headphone out and do you get both channels through that?

[Hugh Robjohns]

I have a marlin 10400 and the left outputs don’t work at all (no audio or power). I’m not too sure what it could be. I’ve tried all the other inputs and turned off phantom power, still no change. Any help would mean a lothttps://youtu.be/8hFd3mji_a8

The signal flow shown in the manual is mix bus - bus amp - rec output - fader - EQ - line out socket and headphone amp and insert socket - power amp.

So with an input signal panned centrally, check the unbalanced record outputs. If they work okay, the problem is probably in the master fader or the Equaliser or the insert socket or the power amp.

If they don't, the problem is the mix bus or mix bus amp.

As Drew suggested, its worth checking the headphone outputs. If the left channel is dead its points to the master fader or equaliser stage. If the phones are working it could be the output driver or a socket problem.

You can check whether the left power amp stage is working by using a Y split cable to route an unbalanced line level signal into the master insert socket (signal on ring contact of the TRS plug).

But in all likelihood it's going to need a competent technician to find the broken bit and fix it...

[James Perrett]

I have a marlin 10400 and the left outputs don’t work at all (no audio or power). I’m not too sure what it could be. I’ve tried all the other inputs and turned off phantom power, still no change. Any help would mean a lothttps://youtu.be/8hFd3mji_a8

The signal flow shown in the manual is mix bus - bus amp - rec output - fader - EQ - line out socket and headphone amp and insert socket - power amp.

Is there a slight hiss from the speakers when they're plugged into the faulty channel? If not the power amp section is dead and it will need to be looked at by a technician. If there is a his then I've highlighted in bold the first thing to check - insert sockets can be notorious and the contacts may need cleaning from time to time.

[Sam Spoons]

The most likely fault with the inserts is the normalising switch contacts becoming corroded or bent. A dummy TRS plug with tip and ring shorted would be an easy way to check (plug it in and the signal will flow through the jack instead). Or improvise by plugging TRS lead and short the T&R at the other end with a coin or something.

[Hugh Robjohns]

I agree that insert connectors are notorious for problems... but the OP also said that the left channel line output doesn't work either.

Going by the online manual, the output signal comes from the EQ, and splits to feed the headphone amp, line out socket, and the insert to the power amp.

So if the line out is kaput it won't (just) be the insert socket at fault.

As I mentioned above, the manual indicates there's a recording output derived from before the main fader and EQ sections, so testing that might give more of a clue as to where in the signal path the fault is located.

[Sam Spoons]

I was assuming the inserts in question were L/R bus inserts. I will read the thread more carefully before replying in future.

[ciarancussen]

I cleaned all inputs and outputs, tried one speaker on each side and still no luck, tried with the microphone too but I’ll try get it looked at professionally. Thanks everyone