Hi I have a mackie sr series 24.4.2.b bus miximg console in for repair,most of it is working except that the right channel output is misssing on on sub outputs 1 and 5 and 3 and 7,i do not think its operating error although i could be wrong,i suspect an ic as gone on the main pcb,left chanenels are coming thru fine,and some right channels do come thru on the other sub outputs any ideas?

Where are you getting the low output? It would be very strange if all channels failed in the same way so it is probably something common to them all. Can you get the clip light to illuminate at all by turning the gain up on a mic channel and shouting into the mic? You are referring to the gain at the top of the strip not the slider aren't you? What happens if you assign a channel to the other sub channel, does the level come up through that? What happens if you take the output from the aux send and you send signal there, is it the same issue?
I may be completely wrong but I suspect if it is only mics that are causing a problem you may have the routing set up wrong or not set a level somewhere else right.

Assuming if you pan hard left on an input it comes out the left and panning hard right goes nowhere and as you say the tape input feeds through to both sides OK there is a very limited number of places where the problem can be. If you are confident open it up and check all the connectors and cables. If anything has come loose this may find it, otherwise it's a trip to the repair shop. The largest cost will be the taking apart and putting back together as the repair itself should be a simple one and diagnostics easy.

Check the settings in your computer in the control panel "sounds and devices" under the "Voice" and "Audio" tabs. Check that all are set to the Mackie instead of the computers default input.

Should be an Aux 1 or 2 output jack on the right side of the mixer. You can come out of the 1 or 2 OUTPUT jack to the input on your processor, and then from the output of the processor to Effects return or to a channel input. By going to a channel input you can then blend the processor's signal with a slider into the sound system with the other channels, while adding tone if needed. By going back into the Effects return, you just blend it overall by adjusting the Effects return knob.
To feed the channels through the processor, turn the AUX 1 or 2 knob up on each individual channel you want to go through the processor. Make sure the AUX 1 (or 2 if you are using that) MASTER knob is turned up on the right side of the console, otherwise nothing will go to the processor. You should see the processors' input light showing signal, if not check your connections. Good luck

This is probably a loose or damaged cable within. These channels I believe are grouped in groups of eight, so two groups would be dead for this function.

Here is your schematic:

http://elektrotanya.com/mackie_1642-vlz-pro_full-sm.rar/download.html

Use TRS to TRS balanced cables from the M Audio to the line in 11 and 12.

Set the pan controls for the 11 and 12 to opposite directions to split the stereo to left and right main outputs. (otherwise both main outs mix the left and right and you get mono result.

Yes, there are chips in the unit and any COMPETENT tech should be able to repair.

Since both the XLR and the jack are bad, this implies something more.

USUALLY Mackie drives the XLR and the unbalanced jack seperately so the problem would be what drives the unbalanced jack.

CHECK if you have output at the UTILITY left output jack. If you do, the driver chip for the left output main is the problem.

If you don't, the problem may back up farther into the EQ.

A LOT of troubleshooting can be done on these by using the block diagram in your manual showing signal paths.

is level pot defectives, needs to be replaced, u can change-them but is very comfusing, needs the same pot ref. u can find on electronics store, but probably dont find them easy, better send to repair. time spend to find them is long.

Without hearing the noise or seeing it on a scope, I can't say for sure, but this type of noise can come from a number of sources. If there is a high signal level on one bus, you could be getting some cross-talk from that channel onto the channel with the higher gain setting. Try to track this down a bit by experimentation. For example, do you hear this with NO connections at all, but with the gain turned up on one channel?

Please try a few things to narrow this down a bit and I'll try to provide you with some options.

Thanks,
Dan

If all other functions work for those channels, the most likely problem is the fader itself. These can fail and operate more like switches rather than faders. Without witnessing the behavior, I can not state that for sure. While these mixers are not the hardest to work on, they are time consuming. The faders can be purchased from Mackie directly. If you need to have this repaired, any shop that repairs audio gear should be able to erpair this for you. Where are you located?

Dan