ONN DVD RECORDER SW8411HDR won't let me finalise discs?

I've wasted many discs recently trying to record from my virginbox hard drive onto my ONN DVD RECORDER SW8411HDR. It used to finalise automatcally if you used up the full disc space or allowed you to finalise after a timed recording. I even tried stopping a recording & then trying to finalise the disc to no avail. It always shows disc as a recording error which is usually never recoverable. Otherwise it plays pre-recorded discs & works fine & the hard disk records & plays back. When it's like this I've tried turning it off but this can only be done by unplugging the unit, can it be 're-booted' or is there a code number to allow a search or 're-boot' of the unit Any suggestions other than buy another recorder greatly received ... many thanks Robin