Zonkbox Died

[robertgroeneveld94@gmail.]

I built this Zonkbox for a friend and when I completed it was working just fine. I ran it on a single regular 9V adapter and played it for about 15-30 minutes; no issues.
After I gave it to me friend, he called me back saying it had died and two of the transistors had developed a bit of a brownish tint to them (pics attached for comparison). He said that when he first turned it on he noticed a huge volume drop (in this instance he was running it off a battery billionaire, which I think was daisy-chained with other pedals). He then plugged it into an isolated output on his Voodoolabs power supply, which he said partially fixed the volume drop issue, but it was still present. Then it proceeded to stop working entirely.

Does anyone know what happened? Did the transistors themselves fail? Did the charge pump cause them to fail?

I'll post pics of the underside of the board once I get the pedal back from him in a few days.

 

[ddenlysm]

I built this Zonkbox for a friend and when I completed it was working just fine. I ran it on a single regular 9V adapter and played it for about 15-30 minutes; no issues.
After I gave it to me friend, he called me back saying it had died and two of the transistors had developed a bit of a brownish tint to them (pics attached for comparison). He said that when he first turned it on he noticed a huge volume drop (in this instance he was running it off a battery billionaire, which I think was daisy-chained with other pedals). He then plugged it into an isolated output on his Voodoolabs power supply, which he said partially fixed the volume drop issue, but it was still present. Then it proceeded to stop working entirely.

Does anyone know what happened? Did the transistors themselves fail? Did the charge pump cause them to fail?

I'll post pics of the underside of the board once I get the pedal back from him in a few days. basketball legends

From your description, I think it was broken because the charge pump device has too high resistance. Looking at the brown color, it looks like it has been burned.

 

[robertgroeneveld94@gmail.]

From your description, I think it was broken because the charge pump device has too high resistance. Looking at the brown color, it looks like it has been burned.

What could cause it to have too high resistance? Just a faulty charge pump?

 

[darwin999]

By any chance did your friend plug it into 12V or 18V?

 

[PedalBuilder]

In addition to what @darwin999 said, check that the transistors are connected and that none of their leads have slipped out of the sockets. If you don’t plan on swapping the transistors out for another set, you might want to just solder them in so that they don’t fall out over time.