How can I fix my Panasonic DVD recorder DMR-EZ28EB?

A statement appears on the television screen to say that "Self Check did not complete" and that I should press ok and then restart the unit. When I prees okay the DVD draw opens and the unit switches off. I then restart it, the drawer closes, the unit display reads U61 and the same instructions appear on the screen that I have just completed. It's a vicious circle and goes nowhere. Any ideas on how I might fix it. The instruction manual is of no assistance!