Help with old soundcraft board

[Jonkan]

Hi, I have recently accuired an old soundcraft 400b board and have found that the left master channel is higher in level than the right.
eg. If i pan a mono signal on any channel to the left it is noticably higher in level than if i pan the same signal to the right.
I can even see the difference in level on my L-R vu meters.

Is there any way I can fix this myself, without sending the damn thing to a tech? (I dont know much about electronics, but i can handle a soldering iron well)

thank you,

Jonas H

[Jay Kahrs]

If it's a modular console shut the power off and unplug it from the wall if you can. Yank the master module out and see if the IC's are socketed. If they are push on them gently but firmly or pull and reinstall them. Clean the contacts where the module attaches to the motherboard with 99% alcohol and a rag, the same stuff you use to clean tape heads. Or, Pro Gold can work to but gets kinda messy. Let it all dry for about 5-10 minutes then reinstall the module and flip the power on.

There is a chance that it could be wiring on the outputs or maybe the internal summing. If your losing exactly 6dB chances are pretty good that the bad side is running unbalanced. Can you pull the output off the main inserts and see if you still have a level loss? What if you run signal back into the main insert return? That'll tell you where in the circuit the problem is.