Group leaking to AFL bus

[kilmister]

Hi all.

Client of mine called me about problem they have with their 4048E/G console.

Signal chain is something like this:
Few channels of kick which are routed to SubGrp 15 (small fader) from it's output signal goes to Fatso and it's returned to last bucket channel E (he's making some parallel compression). Now when he hits SOLO on at channel E there's two groups (gtr, vocs) in same bucket where's Grp15 is and they leak to the AFL bus only. Same thing happens in similar signalchain at GRP16 (snare). Turning bucket 9-16 solves problem, but only for a short time.

I'm going to see console in couple of weeks and thought to ask if anyone has some ideas where to start looking?
Feels strange it's only two groups (gtr, voc) which leaks only if E or F channel is solo'd...

Cheers,
Paavo

[kilmister]

Ok, hopefully problem solved. Client gave me a call and told that one of the two PSU was missing +/-20V rails, no wonder if console behaves a bit strange. Restarting PSU returned the rails.
I recalled incorrectlu size of console, its 4056 loaded with 52 channels...

-Paavo

[kilmister]

Damn, it wasn't PSU. My first guess is fried fet somewhere.


-Paavo