How to recover "disk contains unknown data" error? (Philips DVDR)

I have a Philips DVDR70 and some of my DVD+R disks doesn’t play after having been recorded, getting the message “Disk contains unknown data” on display. I have read that some older firmware version had a recovery function that consists in pressing the “5” key on the remote control while the tray is open, but such function doesn’t seem to work in my unit.

My Philips DVDR70 displays this firmware version information:
DI E2/24277 AN 130322 SV 69
BE 20.3.24 DV not present FP 13
P1_7_b 20040610_1700 dev alead 5.25
BASE_20040607_LFF16k 20040607_1400vp

Could you please help me about how to recover these disks? Maybe must I go back to an older firmware version? If so, where could I find it and how should it be installed?
Thank you very much in advance.

Have the discs been finalised?

Sometimes you can save Parts or more
by Software

infinadyne diagnostic

on your PC

I’ve just run into the same problem with my DVDR-75 after almost two years of flawless service and hundreds of recordings.

In my case, I’ve discovered that newer burns on Tayo Yuden media (T02-00)
would sometimes produce the “unknown data” error, whilst older recordings
made on Memorex (MCC 003) never has reading problems.

Yesterday, I decided to experiment and see if it might be “media” related.
So I used my computer & DVD Decryptor and burned an ISO copy of the problematic disk onto the Memorex media.

Lo and behold…it worked! :slight_smile:
The machine had no probs reading & playing the Memorex disk.
You might try the same procedure and see if it works for you.

ps. Strangely enough, after playing the Memorex disk, the ability of the
DVDR 75 to read & play the problem TY disk was seemingly restored! :smiley:

I wonder if there might be a media-related laser power calibration problem that is intermittant?

I will soon do a few more tests and post my findings if anyone is interested.
Hope this helps,

This problem happens esp. on cheap $1 store discs, and discs without good brand name recogition. TDK and Phillips do great. As far as generics Nexxdata (circuit city brand) burns without problems. I had problems with Maxell, and most other cheapies. With those I do burn to the limit. In 6 hour mode I try not to have more than 5 1/2 hours of video on them.