Blank Blu-ray Discs not recognised on Panasonic DMR BTW700

batman60

Standard Member
My Panasonic BTW700 will no longer recognise blank Blu-ray Discs for recording. Says put in a suitable disc. Get message BD-R needs formatting then ‘cannot format .... may be scratched or dirty’. They aren’t. Have tried BD-R and BD-RE makes both of which previously worked.
Commercial recorded Blu-ray Disc play without problem.
Have tried a cleaner disc.
Any help grateful with this problem.
 

LV426

Administrator
Staff member
My BW780 is the same. My guess is that the laser in the drive has got tired and out of spec. New drive (which may be hard and/or expensive to obtain) probably needed.
 

Gavtech

Administrator
I'm not saying this is the cause, it is entirely a speculation because I have no other evidence at present- but there is a so-called 'DCZ' Drive Calibration Zone which is at the outer edge of the disc. ( There are other fine calibration areas on other parts of the disc used before and during writing)

It may just be possible that a build up of lint and dust on the laser sled bars is preventing the laser sled at the end of its travel from being able to properly address the required areas of the disc.

So perhaps you could try cleaning those and ensure that the sled is completely free.

...but - Just a theory.
 

batman60

Standard Member
Thanks for the replies. I've so much recorded on the hdd that I don't want to lose. I'll try the suggestion from Gavtech. Would appreciate exactly what you meant by cleaning - As I said in original post I've tried new br discs straight out the packaging. Are you referring to the discs or to something inside the unit (sleds?). I'm just a novice at this.
 

LV426

Administrator
Staff member
Thanks for the replies. I've so much recorded on the hdd that I don't want to lose. I'll try the suggestion from Gavtech. Would appreciate exactly what you meant by cleaning - As I said in original post I've tried new br discs straight out the packaging. Are you referring to the discs or to something inside the unit (sleds?). I'm just a novice at this.
He's talking about dismantling the machine and checking/cleaning the area along which the laser assembly moves inside the drive.

This is a picture of the inside of my PC drive which will be broadly similar.
1610612435836.png

The highlighted area is the laser slide. The two lasers are on the assembly closest to the centre spindle in this image, and have to move along the highlighted area to track across the width of the disc surface. It is this that Gav is suggesting may be fouled by accumulated dirt.

As to saved content: if any of it is STANDARD DEFINITION (as apposed to High Definition) then you should be able, if all else fails, to copy that directly over your network onto (say) your PC hard drive where you can deal with it by editing, burning to disc, etc.
 

Gavtech

Administrator
I am reluctant to encourage you to look into cleaning the area that may be responsible especially as I do not even know if this is a likely cause. It is just a surmise on my part.

To do it properly would involve taking the top off the machine and then opening up the bluray drive.
All of that is not without risk.
A small part to yourself, but a much greater risk of doing much more harm than good to the machine if you have no experience in the matter.

I will remark that recordable disk quality is famously hugely variable and that one of the things you should try first is a completely different make / batch of discs.

The discs should always be suspected as the problem first in the event of difficulties, because nine times out of ten they are the cause.

If that bears no fruit then LV426's suggestion is a good way forward.
 

batman60

Standard Member
Thank you for this further explanation. I do not wish, or have the correct skills, to interfere with the innards of the machine. I will try a different make of Blu-ray Disc (when I can get one).
Many thanks.
 

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