R3000 fatal error alternating ink and power lights -main board, CR motor?

Printer was working fine except for a longstanding photo black problem. Was dormant for part of the summer, but did occasional cleanings and alignment checks. Went to print and it stopped dead during the job, alternating power light and ink light flashing. Ran the adjustment program (via 2manuals.com) to read the error messages: “Encoder failure (dirty scale/scale come off,encoder sensor failure) Main board failure, Timing belt step out, timing belt tension.” Also more of the same including “CR motor failure, Paper jam, Foreign material, Harness come off”
Is it cooked? Where to start?

Actually, I let it sit for a few days, pulled the paper out and it turned on. Works OK now with plain paper, going to have to investigate further. Wondering if it might be temperature related.