Often a product's service manual will provide info unavailable elsewhere. I've no connection with Manual Archives, other than paying five bucks to use the site for a week. Why couldn't Philips have provided this info?
I got into a bind when a legacy Philips DVD recorder I own locked up after attempting to finalize a just burned DVD+R. Both Philips website and phone support were no help at all, and the tricks I tried, like performing a full factory reset, didn't work.
I Googled 'Service Manuals' and came up with Manual Archives, then selected Blu Ray DVD Players and downloaded the service manual. The manual shows how to get the damned disc drawer open on the locked up recorder. After the disc was removed and the recorder powered up it operated normally.
In this instance the cause of the lock-up appears to have been an unknown error on the recorded disc. The disc caused the recorder to lock up whenever inserted. I burned another disc, which finalized uneventfully, and destroyed the first disc.
Does that model have the manual release lever under the unit that you slide sideways to open the tray?
You could always ask people on the forum here about stuff like that. Chances are one of us have knowledge on most issues that come up.
Yes, break the tape and slide the lever! You'd think Philips would have made that kind of info available.
The last thread about the 720 was a long time ago.
The 720 service manual not only explained about the release lever but also about snapping the front off the DVD drawer to enable removing the burner from the recorder. So simple when you know the tricks!