Hi everyone!
Not sure if I'm posting in the right forum, but here goes.
I recently purchased a second hand Roger Mayer Concorde treble booster with a faulty indicator LED. Pedal works fine otherwise. The owner told me that the problem could be a faulty transistor next to the LED in the circuit. Tried my local tech but he didn't have a similar replacement tranny (Uraltone in Helsinki, Finland). The original transistor has markings "BC550 C 147". Closest replacement i could find is "BC 550 C B(8?)07" but that one didn't work.
I couldn't find a schematic anywhere on the net, so if you guys have any ideas how to start solving this mystery? It's definitely possible that the problem is somewhere else, not the transistor.
I included a inside shot of the pedal but it's not 100% original. The previous owner replaced the original switch with a 3PDT switch and the wiring colors are possibly different as well. I installed the socket for testing transistors and soldered the LED on top side of the circuit for a better view when testing.
I'll post more info if needed.
Any help is appreciated, thanks in advance!
-TK