flooded russian big muff repair

Started by digthisbigcrux, March 10, 2011, 12:04:21 AM

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digthisbigcrux

so i have an old green muff that was in my basement a couple years ago when it flooded.  recently i decided to pick it up and try to get it working again. 

i had to re run traces, replace the electrolytic power filtering cap, and battery snap.  and i went ahead and changed the jacks to switchcraft panel mounts. 

anywho i got it up and running after some fairly minor (considering the circumstances) repairs.

the only thing is that its quieter.  it sounds exactly the same, only there is a volume drop when its engaged, especially noticeable with the tone lower.

i took measurements of the transistors and they are a little off of the ggg ones found here http://www.generalguitargadgets.com/pdf/ggg_bmp_instruct.pdf but i dont know if its enough to make a difference considering mines a russian, and the ggg one is home made. 

here is what i got

input voltage: 9.38

q1
c 4.56
b .746
e .152

q2
c 4.82
b .144
e .144

q3
c 4.63
b .144
e .134

q4
c 5.6
b 1.614
e 1.022

if the transistors are bad... what are they?  there is green and white paint dots covering up the numbers.  i know that its pretty common to use 2n5088's or 2n5089's in them but they also seem to sound a little more fizzy.

petemoore

   Electromechanicals, switch for instance, and the pots is where I'd test.
  Can be measured in the state they are in, or replaced to get info from a longer/wider base of multi-conditional tests.
  I would think the switch wouldn't like being submerged for long period of time.
  Transistors look biased, and are known to use silicon weather sealant.
Convention creates following, following creates convention.

Paul Marossy

#2
Quote from: petemoore on March 10, 2011, 06:48:24 AM
   Electromechanicals, switch for instance

Yeah, I was thinking that the bypass switch might have gotten a bit corroded and can't make a really solid contact anymore.

digthisbigcrux

pots are fine.  bypass switch is fine.  i even jumpered the lugs on the switch and saw no rise in volume.

i could send pictures of the scope at different points in the circuit if that would help.