EEVblog Electronics Community Forum

Electronics => Repair => Topic started by: rg58 on December 28, 2017, 04:30:58 pm

Title: Panasonic DMR-BCT820 Blu-Ray - Disc read error - NoREAD - Laser? Service Menu?
Post by: rg58 on December 28, 2017, 04:30:58 pm

Hi all,

Last night this BluRay recorder Panasonic DMR-BCT820 (similar DMR-BCT720/721) stopped playing back BluRay Discs that have been recorded on the same device. The day before it played back the very same disc perfectly - the disc hadn't been taken out and stayed in the drive. Later other BR discs have been tried, including an empty one - all with the same result ('Incompatible Disc'). Overnight I disconnected the recorder from the mains and plugged it back in this morning, but the error still persists. A commercial DVD also failed to play back ('Disc not readable'/'Disc nicht lesbar'). So basically the BluRay drive has DIED last night.

How it happend:
In the Disc Menu all BlueRay contents showed up, but upon selecting and pressing the OK button on the remote control, the recorder would just switch back to TV (removing the menu/OSD). Accessing the disc menu again, selecting various other recordings on the same disc, the same happend. Then, at some point, it suddenly showed 'Inkompatible Disc' in the menu (since then I was never able to access any disc again). I then changed the disc for another one, and a rhythmic scratching noise was heard from the drive several times. I assume the drive was looking for the TOC and the laser went back and forth.

Questions:

1) Has anyone experienced this problem before with the Panasonic Bluray DMRs and know how to solve this problem?

2) How can we access the Service Menu on the Panasonic DMR-BCT820/720/721? Would I be able to run a self-test or test the laser from there?

3) Appart from cleaning the laser, what else could I try? Are there any adjustments that could be done? (I'm equipped with scopes etc.)

The recorder was purchased in 11/2012, was quite expensive and did an excellent job until now. I am not willing to replace it, nor sending it for expensive repair (>300 EUR?).

Thanks a lot!

Title: Re: Panasonic DMR-BCT820 Blu-Ray - Disc read error - NoREAD - Laser? Service Menu?
Post by: rg58 on January 03, 2018, 11:11:55 am

I have tried a cleaning DVD with brushes today (HAMA DVD/BluRay Cleaning Set). It was recognized by the drive on the 2nd attempt, a video was playing during the cleaning process.

However, the drive still doesn't play back any other DVD or BluRay Disc for some reason ("NoREAD" shows in display & "Incompatible Disc" on screen), tried several different ones. I can only make the Cleaning-DVD play back in about 1 in 3 cases. What's the matter here? Why it doesn't play back any other DVDs and BDs anymore?

Btw, I ran the cleaning cycle 5 times now with the same result. The software is 1.25 which is the latest.

What else can I try? Is taking it appart my only option now? Does anybody know how to access the service menu?

Thanks!