Dvd willnot record, keeps saying defect in disc

I have done the reset, cleaning, ect... I also bought an exact same refurbished machine so I could finalize the recorded discs I did not finish up.. when I hit record (on both machines this happens) a msg says defect in disc is found the scheduled event was not recorded and this disc is beeing finalized to protect andy recordings on this disc (which there are none since it is totally balnk). I have purchased 3 different brand of recordable discs.. all have the msg pop up- here's the really strange thing when the old unit went out I had 6 discs that each had 1 movie recorde on them when I put them in the 2nd (refurbished) unit it was able to record on those discs. It will not record from VHS to DVD either same msg shows up, Yes I have checked & souble checked the connections, the first DVD recorder - recorded about 600 titles- so the connections r working did the same set up w/other machine. I am at a loss plz help