I just bought my husband the PS2 Band Hero set for his birthday today, and right out of the box, one of the drum pads seems to have stopped working (it worked for a couple of songs and then stopped). Everything else seems to work fine, we checked all the connections, all the obvious stuff checks out. Any ideas? We’ll be going back to the store where we bought it, too, but I’m hoping for an easy fix here. 
I guess no easy fix then. 
I’ve never taken my Guitar Hero drums apart, but I did fix the drum pedal when it stopped working. It uses a piezoelectric sensor, and the drums and cymbals do as well. In the case of the drum pedal, one of the wires had come off, and I had to resolder it. You’d probably have to remove all the screws from the bottom and look inside.
If you hadn’t just bought it, it would probably be an easy fix (if you can use a soldering iron). Since you did, probably better to return it and get a replacement.
I agree; just return the thing and swap it out for one that works.
Back to the store it goes, I guess.
I’ll have to remind myself in future not to hit the pads with quite so much enthusiasm – I had a percussion teacher way back in the day admonish me for being too tentative, saying, “I can’t break that thing, Jimbo; I’m quite sure you can’t either.” Since then, I’ve never been too shy about playing hard. 