Well if you can't get it open to check, then the answer is pretty much no, it can't be fixed. I don't have that mod, but i have others that I had to open.Not sure how do that. I have a punisher 80. Do you know how?
Can you get to the IC board, to remove the cover on the power button? If so, clean it with a qtip dipped in a tiny bit of alcohol. It should look like a tiny metal box with a little black push button on top. Push that a few times to make sure it is moving. If that works put a tiny bit of paper (one sheet thickness will do it) inside the plastic button where it goes over the switch and try that. Not knowing the history of the mod, we don't know how much junk the previous owner let get inside, so maybe just making sure the switch is making contact will work?I figured out how and everything seems to connected