Pioneer Elite PDR-99 system problem

I own a Pioneer Elite PDR-99 CD recorder, which I bought used two years ago and which has worked perfectly--until this week, when I began getting a blinking "check" message whenever I inserted a CD. The CDs aren't the problem--I get the same response when trying brand new CDs, blank CDs, and other CDs that play without any problem in my back-up player. According to the manual the cause is "a system error that occurred due to noise of static electricity." It advised unplugging the power cord and plugging it in again, which didn't work even when I experimented with other power strips or wall sockets. Any ideas? Any notion of the repair cost?