Replace the HDD in a DMR-BWT720, keep the recordings

[jonoro]

To replace the HDD in a DMR-BWT720 without losing the recordings.

I posted last year that I thought that it must be possible to save the recordings when changing the HDD and that it probably required the serial numbers of the HDDs to match. Well it is both the serial number and the model number that have to match, possibly the size of the disk too; I have only been looking into replacing the HDD with one of identical capacity so cannot confirm the latter.

Well the HDD change can be done!
I have replaced the HDD in one of my 720s and kept all the recordings. I think the same procedure would probably work with other Panasonic HDD recorders.

What is required:

• A PC running Widows (XP or later) and the ability to attach a SATA drive directly to the motherboard. It will not work if you try and use a USB to SATA adaptor.
  
  
• A bootable CD or USB with a flavour of Linux on it. I used Ubuntu - Download Ubuntu Desktop | Download | Ubuntu
  
  
• A copy of Victoria - HDDGURU: Victoria (free)
  
  
• A licensed copy of WDMarvel v3 – WD Marvel Repair Tool – Utility to recover HDD WD Marvel (A free demo version is available and whilst good for testing your hardware setup it will not write to a HDD and so can not be used. Cost is currently 15USD for one month’s use.
  
  
• A WD 1Tb HDD using a Marvel controller. I fitted a WD 10EURX, about the cheapest 1Tb drive around. It has to be a WD Marvel drive as you will be using Vendor Specific Codes to change parts of the HDD’s passport.
  
  
  
  
  
  Two parts to the procedure:
  Clone the HDD
  Change the HDD’s passport.
  
  
  Clone the HDD
  
  For this I booted into Ubuntu and then used the DD command to clone the drive. If your drive is failing you might want to use DDrescue – details here:
  
  Ddrescue - GNU Project - Free Software Foundation (FSF)
  
  I attached both old and new drives at the same time using a USB3-SATA adaptor (adaptor OK for this step) for one drive and straight SATA for the other. This took 7 hours to clone. DDrescue will take much longer. It’s useful if using DD to make provision to monitor progress such as PV or “status=progress”.
  
  
  
  Change the new HDD passport to partially match the old HDD
  
  Boot into Windows and run Victoria. Connect each of the HDDs one at a time (USB caddy OK for this) and select from the available HDDs and then press “Passport”. From there make a careful note of both the Model number and Serial number of both the old and new HDDs.

• Connect the new HDD to a SATA port and reboot the PC.
  
  
• Run WDMarvel and enter the licence number you have been emailed after paying the 15USD. (you need an internet connection for the number to be verified and the writing function to be enabled.
  
  
• Select the new HDD from the list on the left and then press “Detect”. The “Drive” box on the right will populate with passport details of the HDD you have selected. As likely you will not know which HDD to select from the list just go through each of them, note many non-WD drives will not report their passport.
  
  
• Select the “Heads” tab and then “Change serial” and enter the old drives serial number.
  
  
• Repeat the last step but for “Change Model number”
  
  
• Select the “edit config” entry and then untick the entry for “use Model from flash”
  
  
• Click on “Save to SA”
  
  
• Reboot and check with Victoria again that the model number and serial of the new drive match those of the old drive.
  

Install the new HDD and away you go.

None of the above steps will make any changes to your old HDD and it can still be put back in the Panny. If the Panny still asks for a format then something has gone wrong but as long as you don’t format you can still put your old HDD back and the recordings will still be there.


Note the replacement drive must be a Western Digital one with a Marvel controller. Each HDD manufacturer uses their own specific VSC (vendor specific codes) to write to the SA (systems area) of the HDD. The SA is hidden from normal use and employs techniques such as negative cylinder numbers for access. The passport is stored in the SA and in part in the on-board ROM.

Warning – WDMarvel is very powerful and it is easy to make an unintended change that turns your new HDD into a brick.

Good luck

 

[rudman]

Ho Jonoro
Thanks for this heartening article.
I would like to rescue the contents of the failing disk on my Panasonic DMR-BS880EBK.
I have managed to obtain exactly the same model disk as the original (WD5000AAVS-14N7B0) but still need to be able to change the serial number to convince the machine that it's the original.
A few questions arise:
* Am I right in thinking this is a WD-specific firmware serial number, or is it just the "Volume Serial Number" shown on the (DOS) command line DIR results - in my case, 76A6-21E8?
* Victoria does not work on Windows 10 64-bit. Do you know of any other products which would do the same job?
* How do I know if the drive has a "Marvel" controller? You seem to imply that WDMarvel only works for this kind of controller.
Thanks
John

 

[jonoro]

Hummh!
That was a couple of years ago.
I only set out to prove the myth wrong that you couldn't use a new HDD and keep the recordings.
Once I managed it I lost interest.
I recall I had many attempts.

However to try and help...
Firstly I urge you to take an image of the failing HDD using DDRESCUE.
Keep this safe.
IF your 880 is like the 720 then powering up with a different HDD it will call for a reformat.
WHAT I DON'T KNOW is if you decline the reformat and put the old HDD back will it insist on a reformat of the old HDD. This is key for you I suggest - do you only get one shot with a new HDD or can you abort and try again?

The serial number that you refer to is NOT the HDD serial number, this is just a number DOS allocates when formatting.
The real serial number, and model number, are stored on the disc platters but in an area you, and DOS, cannot see. Negative cylinder numbers are used to access this SA, or Systems Area.

You may not need Victoria as I only used it during investigation to discover the srial number and recorded model number. Marvel should be able to read this. WDMarvel is available free I believe as a read only demo.
If you wanted to run Victoria you could try runming a VM under x64 windows.

I believe that the Marvel controller is more a case of HDD that are compatible with the WDMARVEL app.

You may have better luck with ignoring the recordings when installing a new HDD and recovering the recordings from the old drive/image of it. I did start a thread on how to fo this some time ago.
Isobuster I recall was quite good at thid.

 

[rudman]

Yes, thanks. The obvious solution is to install the new HDD, have the PVR format it, so that it registers the new serial number (in EPROM?), remove the disk to a computer, then restore the o/s and program files using some disk imaging software. What am I missing?

 

[jonoro]

That sounds like a good plan.
But you will have to first install some code on the new HDD otherwise the unit will report a HDD failure and refuse to format.
I have another thread with how to do this on a bwt720. You could adapt this, the code you will need for your 880 may well be different from the 720.
The code is omly the first x bytes of your old HDD. Iwould use ddrescue to copy in case your HDD errors arein the first x bytes. I found x by trial and error, it is not critical at all. Too small and it won't work but too big and it just takes longer.
Suggest you start with the value for x the same as I use for the 720.

Once you have this code, into the 880 and format.
Then on a pc copy across all the rest of the data starting at x+1bytes (during the format the unit changes just a few bytes).
The serial number and model type must be stored in EEPROM on the unit.
The code for the os is not on the HDD, this is a myth.

Good luck. I would still urge you to keep a full image of your HDD, just in case!

 

[jonoro]

I just looked back
170200 hex is the value for x I used.
Here is my earlier thread.

Panasonic720-Installing a New Internal HDD- How to do it

I have read much on this and other forums re the impossibility of replacing the internal HDD in the 720 without getting either a genuine spare part HDD or an impossible to obtain “Service Disc” to “format” the HDD. It’s reported that there has to be a “special partition” on the HDD that the...

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