Dead TS-9 - Suggestions?

[the.blode]

A while back I was replacing some parts in my TS-9. IC went fine, but after replacing one of the caps, the pedal would no longer light up under dc or battery.

I forgot about it for a while but I've just come back to it to source out the problem. The Cap measures fine and there is no other easily identified problems, so I'm thinking that heat on the board must have damaged the switching circuit. I can't measure any bias on the IC. At the moment, i'm really not sure what to do about this - any suggestions?

[Mark Hammer]

As always (and you'll forgive the repetitiveness of this), I recommend cleaning the flux off the board with some methyl hydrate and a used toothbrush or cotton-tipped applicator.  The intent is to make any unintended solder bridges or cracks a little more easily visible.  As wonderful as solder flux is, it dries shiny, and has the nasty habit of reflecting light in ways that can interfere with accurate detection (or discounting) of solder bridges.  Given that you've replaced parts, the risk of bridges or cracks is always there.  Eliminate that possibility from your list, and yo can safely continue with other well-worn troubleshooting tips.

[Electron Tornado]

If the pedal is getting no power at all it's possible that you pulled a wire loose or bumped another component and created a bad solder joint.  If you have a volt meter, start tracing from the battery and find where you no longer have any voltage.  A quick way to tell if the pedal is not getting power at all is to see if it will pass a signal in bypass mode.

[zombiwoof]

Was the cap you replaced an electrolytic cap?.  If so, maybe you didn't orient it for the correct polarity.

Al

[the.blode]

I always keep my boards clean with meth, and check them over regularly for bad solder joints.. There's definately nothing obvious. The cap I replaced was an electrolytic to a polyester film, so polarity isn't an issue.

Electron - your last sentence is what makes me inclined to think that the problem is based in the bypass. TS-9 has a buffered bypass, and it's not passing anything, so the FETs used to bypass the IC gain stages aren't opening