Zakk Wylde Wah - No Audio on active channel - debugging help

[Archangel465]

Hey all
Recently had a friend come to me to repair his Zakk Wylde signature Wah, there was absolutely no sound coming through it at all
I opened it up, tested and realized the footswitch was totally dead, so I replaced it.
So then the bypass channel began working, but now on the active channel the only sound is this weird high pitch whine which adjusts itself when the pot is adjusted
Help please!

[thermionix]

weird high pitch whine which adjusts itself when the pot is adjusted

Working wahs will do that when you hook them up backwards, plug the guitar into the output, input out to amplifier.  Easy mistake to make when you're looking at a pedal upside down.  So, check that first.

[Archangel465]

Thanks so much! Guess I had been looking at it upside down for so long that I just forgot. Totally fixed it, thanks mate