The No OPC message means that the unit can't record. The laser power calibration for the burner failed the internal test with that disc. Was the disc a blank disc? Make sure that you use a clean CD-R or unfinalized CD-RW. Try a different lot or brand of CD-Rs or CD-RWs. If the problem persists, then the laser on the recorder is damaged. If the unit is under warranty, contact Philips. However, based on the date given on the manual, this may not be worth finding a shop to fix the unit. DVD/CD burners for computers are fairly cheap but I'm not sure of the specs for a replacement CD burner for inside this unit.
The manual is available from Philips here: www.p4c.philips.com/files/c/cdr765bk/cdr765bk_dfu_eng.pdf
. The trouble-shooting information is on page 21 (page 23 of the PDF).
I hope this helps.