DS-1 acting stupid after it's been on for a few minutes

[ayayay!]

Schem:  http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=5779&g2_serialNumber=2

Issue:  Pedal is fine in bypass.  When effect is engaged, after a few minutes of playing, some wooly distortion starts building underneath the guitar signal.  Then it takes over eventually.  Nothing but static.  Sometimes flipping the pedals a few times brings it back.  Sometimes the engaged signal is completely muted.  Sometimes it comes back completely normal again.  Again, fine in bypass, but can be static-y or muted when engaged.

This sounds like the nasty dying-cap sound that you often hear in amps.  I swapped the flip-flip ground cap c22 with a new one.  (I had read somewhere at one time that can often lead to flip-flop failure if it's bad.)  I also swapped Q6, Q7 & Q8, no difference.  The flip-flop itself seems fine as well.  I've quadruple checked all the cabling and looks for any leads or components that may be exposed or grounding out, nothing found.  Since the nature of it is that it fails over time, I'm really thinking this is component failure.  Finding which component (like I said, I suspect a cap) is the trick.

I have used an audio probe and traced it all the way through.  Nothing found.  Makes it really a pain too that it starts after 10 -15 minutes of playing. 

Ideas? 

[italianguy63]

Heat related failure?  Look for a component that heats up?

[ayayay!]

Yeah, sounds like it, right?  Nothing's warm to the touch.   

[italianguy63]

Dumb question-- batt power or wort?  (Bad battery?)

[ayayay!]

Power supply.  Not a dumb question. 

[italianguy63]

I'm out of ideas on my limited knowledge, but I would bet semi-conductor.

[duck_arse]

pull out C2, C5 and C9 electros, replace with polys. then C14 and C8, more polys. see what is then.

[ayayay!]

pull out C2, C5 and C9 electros, replace with polys. then C14 and C8, more polys. see what is then.

Those are all already upgraded to metal film.  :/

[ayayay!]

Bump

[Seljer]

Some voltage measurements on all the semiconductor devices couldn't hurt. Might be able to spot something funny.

[Quackzed]

elecro's ... you just can't trust 'em... i'd give any electros the bad cop treatment... and if they even blink, rip 'em out and replace 'em.
maybee try wiggling the electros with the thing plugged in and powered, see if you can get it to do its weird failure thing...

[MrStab]

Sometimes flipping the pedals a few times brings it back. 

do you mean switching it in & out of bypass? if so, my instinct would be to check the switching section (assuming it's not a clone)