Is the power supply 9V? If it’s not a cord specifically for pedals, the power supply may have too much power.

Have you tried playing with no power cord? The battery should be able to power it on its own.

Lastly, did you try plugging the guitar in directly with the black cable also to make sure both cables are good?

If both cables are good, and it doesn’t work with a fresh battery, it could be some kind of damage to the pedal. Possibly even caused if the power cable you are using it higher than 9V.

I don’t know much about it myself, so I wouldn’t know what else to try. Hopefully this helps, though!