Wytron 3000 stand alone won't copy

I have recently purchased a Wytron DVD 3000 stand a lone unit 1:7. It is a used unit, and came with no instructions. I have had no success in copying anything. I think that it is the disc that I am using. They are DVD+R. That should work, right? The lenth is well within the 240 minutes that the disc can hold. I have read the manual on line. NO HELP! Is there anyone who knows something about these and could help. I am desperate!:sad: