It's probably a paperweight now.
If you know what chips to order & know how to solder you could fix it.
I had a guy that tinkered with them as a hobby that repaired a few for me, but the last time I sent him one everything went south. He has not returned it (it's been about a year) and will not reply to email anymore. I wish someone in this community with the skills & knowhow would start repairing them. There is a market, and I haven't found any repair options out there. Most 'repair' places that I've found for iRivers on the net can't do anything more than change out batteries & hdd's. Maybe even swap out boards, but not actually solder new chips on boards like what is needed for all these fried units laying around.