Behringer SL2442FX , mixer desk, 2004

googling around turned up

"Incidentally, on more than one occasion I have repaired a Behringer with this exact same symptom (no L ch), and it turned out that one of the main bus tracks runs right at the far right edge of the PCB from fader to output jack socket section. When the PCB was installed into the chassis, something sharp caught on the PCB and partially cut through the track, which eventually failed some time later."

for when I get in there proper

I have also experienced this exact same problem, it is part of the casing that does the damage if you are not very careful when fitting the PCB. The track is VERY close to the edge.

Gareth.

with

main

Got into that panel now Although no observable damage to that trace, I may as well run a line // to this trace while in there. Looks like that mod, replace the 2 4p c/o sw , the 2 1/4 in sockets for Insert and at least remove the main slider , probably replace. Putting some alternate sets to the pins of the interboard headers, and keep fingers crossed. After that, should it bounce, I suppose its a matter of building an active buffer and LEDs as telltales , half way through the outer stages, to localise down a bit. I will try and advise the owner to swap to using the upper channels , in case its a problem earlier on.

Should it bounce, I suggest you get the owner to buy a new one with a 3 year warranty for £240.

Probably far more cost effective than hours of repair bills plus parts on an

8 year old mixer probably worth something like £70 in good nick on ebay.

Gareth.

Force on the 0.25 socket L insert sw about 700gm, to break contact, about

1400 gm on the R to break contact is a bit suspicious. Normally I would expect problems in the order of 300 or 400 gram contact force. Found a pair of 4w c/o switches to fit in the 13.5mm of clearance space.

To desolder the 4p c/o switches you need to sling .6mm wire under the sw body and pulling when desoldering. Normal clamp force over the body is enough to break-up the casing of these very weak switches. At least I could see inside and no wonder they're problematic.