Had something similar happen to a Randall ss, rg75. The lead channel lost volume, smoked, and was never the same again. Luckily, the amp still powered up and made noise on the clean channel. Got donated to a kid learning to play.
Good luck with the PF and let us know if you get it fixed.
If its not powering up could be a blown fuse and it sounds like you could have toasted a resistor or some other ss component. That being the source of the smoke. I would open up the amp and look for something burned up and check the fuse.
Same thing happened to mine before Christmas, I'm pretty sure it was the output transistor burning up. So much smoke and it stunk! Was fixed under warranty. Wonder if there's a bad batch out there? Maybe it's linked to them stopping production too, who knows?