I bought a broken Dunlop Cry Baby 535q Wah Wah pedal recently to re-purpose as a teensy controller or passive volume pedal. When I tried it out, though, it worked perfectly. Later it started making really loud static noises whenever it was engaged. I figured it had a loose component or one that was overheating. There was an easy fix, and one I did not find anyone mentioning online, so if you have a noisy 535Q, try this.
After taking apart too many pieces (hint: never remove the pot/PC board assembly if you don’t need to!) I discovered that touching a micro transistor, Q2, made it work again.
Since pressing helped, I decided to reflow its solder joints, and that did the trick! It’s been working great for a month now. Not bad at all for $20.