If you’re just bought a new Lexmark Laser and are getting firmware or fuser errors, it may not be DOA. Try powering from a different outlet in your office or home that’s on a separate breaker first before you return it or call for service.
Had two issues, the first on a X264 which is a phenonemnal machine for a B/W unit. Couple dozen deployed, never a paper jam that wasn’t user caused (wrong paper, too thick envelopes, printing same paper about 2 dozen times…, seen it all). Client just purchased one, started complaining of fuser errors. Had it replaced. After googling a bit, found they’re ground sensitive. Changed the outlet and got rid of the dollar store power splitter he used – run perfectly since.
Another client – small home office, the color CX310DN – similar issues. After two DOA units (fuser error on boot or by 2nd page printed), third one arrives DOA – fuser error again on boot. One DOA possible, two, unlikely but not impossible. Three, something got to be wrong. Try a different outlet in the house and voila, no more fuser errors.