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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB: The Classic Live Audio Board => Topic started by: Frank Czar on October 28, 2017, 03:05:45 PM
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Hi Guys
I have an M7 that has started doing something strange, when turning the console on it fires up like normal but will not pass audio, if I restart it it will then work. That was a few months ago and now it started taking multiple attempts to get audio to pass. Any ideas?
I will try loading the latest firmware but cannot do it at the moment, I think it is version 3.5 in it now.
Thanks in Advance
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Hi Guys
I have an M7 that has started doing something strange, when turning the console on it fires up like normal but will not pass audio, if I restart it it will then work. That was a few months ago and now it started taking multiple attempts to get audio to pass. Any ideas?
I will try loading the latest firmware but cannot do it at the moment, I think it is version 3.5 in it now.
Thanks in Advance
That looks like a word clock issue. Try attaching an external Word clock and look if it will fix the issue. Otherwise you'll need to replace the dsp board.
Enviado desde mi VIE-L09 mediante Tapatalk
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It could not hurt to open it up and "exercise" all of the internal connections.
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It could not hurt to open it up and "exercise" all of the internal connections.
Not the same problem, but we had an M7 that had the 2nd from the left section completely die. Inputs 9-16 and 25-32. No fader movement, no lights functioning. It was still passing audio and could still be mixed from the CL section, the idea with which the operator was willing to move forward (thanks Ed!). We opened it up and reset the ribbon cables before showtime and all was well again. Haven't seen that issue recur.
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Analog *and* digital outputs muted?
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Hi Guys
I have an M7 that has started doing something strange, when turning the console on it fires up like normal but will not pass audio, if I restart it it will then work. That was a few months ago and now it started taking multiple attempts to get audio to pass. Any ideas?
I will try loading the latest firmware but cannot do it at the moment, I think it is version 3.5 in it now.
Thanks in Advance
We have been experiencing the same thing with the 3 M7 consoles we have, 2x 32Channel and 1x 48Channel.
Recently, one of them has taken a turn for the worse and will now not output any audio at all from the analogue outputs and the analogue inputs either intermittently are distorted or sound one-legged. A power cycle usually fixes the inputs but not the outputs.
We've got it in for service at the moment so hopefully they can fix it, however we tested the slot cards I/O as well and regardless of what happens with the analogue I/O issues, the slots work perfectly.
Maybe if you are able to use the slot I/O to get you around the issue for now until a fix is found?
ETA: Things also tested include: External W/C and Internal W/C, Re-initialising the desks, Flashing the desks firmware. We also checked various analogue inputs and outputs to see if there was a pattern but there wasn't in our case.
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Intermittent problems usually require a 'round up the usual suspects' approach. For starters can you establish if audio is arriving at the console i.e. are you seeing level on the channel meters even if no audio is arriving at the outputs? Can you get audio out of the signal generator even if you can't get audio into the board? Best places to start in consoles that are many years old is the PCB connectors. Disconnect and reconnect all internal ribbon connectors and other interfaces to wipe off oxidation. Another suspect is the back up battery. As it's output voltage sinks over time it may intermittently fall below the minimum value before it dies entirely and it's contacts may be oxidizing as well. Replace it as you would any computer back up battery.
I have an M7 that has started doing something strange, when turning the console on it fires up like normal but will not pass audio, if I restart it it will then work....
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UPDATE
To answer your question Riley, yes it does show signal, and all functions physically work
just no audio on any omni out, audio will work after 10 -20 power up cycles and the board will function perfectly.
I reloaded the software, replaced the battery, "exercised" the connectors, same thing.
Any ideas? Any good service centers in Central FL.?
Thanks Guys
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No idea about service option in S Fl but a couple more questions. Do you get anything out of the headphone jack? Do you have any output cards installed or can borrow to see if you get output from those? It’s entirely possible that the DC rails on the Omni board(s) are locally regulated and you simply have a regulator IC going bad. That’s probably an analog world POV, I suspect that even if such a thing is the case it’s still a PC board swap.
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You can find service manual PDF on the net easily if you haven't already done so. It contains detailed circuit diagrams among other things.
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No idea about service option in S Fl but a couple more questions. Do you get anything out of the headphone jack? Do you have any output cards installed or can borrow to see if you get output from those? It’s entirely possible that the DC rails on the Omni board(s) are locally regulated and you simply have a regulator IC going bad. That’s probably an analog world POV, I suspect that even if such a thing is the case it’s still a PC board swap.
It's almost certainly a board swap. The M7CL power supply just provides something like +20vdc - that goes into a big board under the center section which turns that single voltage into every other voltage needed by the various sections of the mixer.
It's sometimes useful to check to see if any of the digital outputs work, such as the AES output or one of the card slots. But really it's likely that one big card with a bad section feeding the analog outputs. You can measure voltages at the heavier ribbon cables which carry power; there's often even a legend by the connectors.