Please can soneone help. On startup my DMR ES15 makes 5 chirps (4 lower tone and 1 higher tone). These chirps would occur whether there was a disc inserted or not; i.e., the unit could no longer tell if there was a disc in the tray. Powering up without an inserted disc used to be quiet (because there was no disc to read from) but now it chirps on power up. The first time this occurred an error said there was a problem with the disc but also displayed a "U61" error message. That went away but the unit could still not read any discs, and powering down and back up (several times) to reset the unit did not work.