Really random trouble with my russian Big Muff-Debug help?

[Benjamin]

I left for a few months for school, come back and start playing around with my normal rig. The russian big muff I aquired a while back isn't working. The LED lights up, so it is powering on, but no signal passes through. I opened it up, and I didn't see any loose cables or cold solder joints, so I could use some guidance as to where to go from here.

thanks

[puretube]

put in a fresh battery - stomp the big switch about 23 times - fastly rotate all knobs all the way from left to right and back 7 times - plug both cords in and out at least 3 times.

[Benjamin]

thanks.
How about a response worth reading?

[puretube]

read again thoroughly :evil:
and repeat each step 10 times! (except the battery step 1).

[aron]

One option is to build an audio probe and probe through the circuit, after doing what Puretube said.

Check the signal at the base of each transistor to see where the problem may occur.

Make sure each transistor is getting power at the collector.

[goosonique]

Well you can dunk it in a pail of soap water .... or you crack it open (screwdriver please) and just check it out..... I have learned alot through this eventho it is painful at times.... :lol:

[Mark Hammer]

Ton's right.  Sometimes, you leave stuff sitting there long enough and air-borne gremlins coat your contacts, rendering them unreliable.  I have a small table radio beside my side of the bed (with an 8-track player!) that I've owned for over 20 years.  When I don't use it for even a few days, the volume pot crackles and acts eratically.  Vigorous rotation tends to help the problem.  There are also a variety of contact restorer chemicals out there.  A buddy with a pro-studio recommended some stuff to me that went for somewhere in the $25-40 a vial range (and I mean *vial*, it was about 10ml).  He described it as essentially a one use solution (i.e., put it on once then pass the equipment on your grandchildren).

Of course, then there's other stuff.  I loaned my Korg Pandora to a neighbour's kids about 11 months ago with a fresh set of batteries in it.  When I finally asked for it back two nights ago, it would seem that the last time they had used it might have been about 10 months back because the batteries had leaked out all sorts of crap and now looked like leprosy victims.  Of course, it won't boot now, and even after a serious Q-tip swabbing of the acid and residue I hear a sizzling sound when I put new batteries in (the new AA batteries lose about 300mv in a matter of 15 seconds so there is a short somewhere).  Sadly, that's one of those instances where turning it on and off has considerably less restorative power than in your situation.   :cry:

[petemoore]

thanks.
How about a response worth reading?

Well not exactly a response, but the debugging pages have alot to offer about finding problems.
 I've 'erased' stuff off jack wipers, using a pencil eraser. Pots and jacks [mechanical connectors] could alternately be replaced with known good ones, but this too could introduce new problems also.
 It could be a serious problem, or just a wire that 'looks' good. All conclusions aside, probably something quite simple.

[Paul Perry (Frostwave)]

The footswitch in thos Russian muff s have caught me out more than once.
And, the switch pinout is non-standard.

[goosonique]

those "electronic contact cleaners" come in handy all the time .... just like magic ....