Transferring hard drive to new machine.

Dosalmendros

New Member
Hi all, I'm new here, so apologies if I've not followed protocol or am in the wrong place.

The motherboard on my 1TB Fox T2 died, so a bought a used 500GB model and fitted my 1TB drive.
Seemed to work OK, recognised the size and said it was 65% free.
However, when trying to play the existing recordings, it just says "the channel is scrambled or unavailable"
Is it possible to recover the existing recordings, or must I format the disc?
Thanks Bryan
 

af123

Administrator
Staff member
Is it possible to recover the existing recordings
I'm afraid not, the recordings are encrypted with a key that's unique to the original motherboard.
For the future, if you install the custom firmware then you can get it to decrypt everything on an ongoing basis.
 
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Dosalmendros

New Member
I'm afraid not, the recordings are encrypted with a key that's unique to the original motherboard.
For the future, if you install the custom firmware then you can get it to decrypt everything on an ongoing basis.
Thanks for that, I was afraid that was the case.
Any chance of copying the original key to the new motherboard?
 

Black Hole

May contain traces of nut
Any chance of copying the original key to the new motherboard?
No.

See Things Every... (click) section 5.

It occasionally occurs that the HDR-FOX "forgets" its key, and it takes a power cycle to restore it. I infer from this that the encryption is symmetrical (ie uses the same key for encryption and decryption, which is probably the case for efficiency), and that the key itself is held in volatile storage which has to be loaded from non-volatile storage at boot. However, this storage isn't necessarily part of the code area and may be completely inaccessible without hardware tools, and even then it may be embedded in a chip and not snoopable. And even if you could, programming it into another machine is a magnitude more difficult than finding out what the key is in the first place (although it might be possible to recreate the decryption off the box, if the key was known).

Ultimately: it's only telly. How much effort does it warrant?
 
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Dosalmendros

New Member
No.

occurs that the HDR-FOX "forgets" its key, and it takes a power cycle to restore it. I infer from this that the encryption is symmetrical (ie uses the same key for encryption and decryption, which is probably the case for efficiency), and that the key itself is held in volatile storage which has to be loaded from non-volatile storage at boot. However, this storage isn't necessarily part of the code area and may be completely inaccessible without hardware tools, and even then it may be embedded in a chip and not snoopable. And even if you could, programming it into another machine is a magnitude more difficult than finding out what the key is in the first place (although it might be possible to recreate the decryption off the box, if the key was known).

I guess the manufacturers must be able to program the key on the production line, but it may be a ROM that once programmed can't be changed
Looks like I'll just have to format the new drive.
Thanks for you help, at least it will all work again.
 
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Black Hole

May contain traces of nut
You may not appreciate that the "ROM" in question could be (probably is) inside the system-on-chip that handles all the video processing, and programmed using a special serial production interface (JTAG). It's not impossible to gain access to the JTAG, but it would be all-but-impossible to interpret the serial data from it (which may have the key, but mixed with a load of other configuration stuff) without access to the design information.
 

af123

Administrator
Staff member
I believe it's is a special area of the flash chip (that's certainly one of the features of that chip based on the data sheet. )
If you could transfer the flash chip over then it might work but would involve a lot of microsoldering - well beyond my abilities.
 
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Dosalmendros

New Member
I believe it's is a special area of the flash chip (that's certainly one of the features of that chip based on the data sheet. )
If you could transfer the flash chip over then it might work but would involve a lot of microsoldering - well beyond my abilities.
Thanks Guys, I have reformatted the drive and everything is working now.
Ok I lost all the recordings, and Her Indoors is a bit miffed, but hey it's only TV and not the end of the world.
I'm a retired Engineer and have worked on surface mount devices, but no longer have the tools or the motivation (or the eyesight) to play with them now.
 

af123

Administrator
Staff member
I think it would be a tall order for anyone .



JTAG might be an option but nobody has done much with it beyond extracting the boot loader.
 

Black Hole

May contain traces of nut
Ooohhh... a ball grid array, huh! Pretty bloody tricky. Not too bad to assemble in the first place (with production tools), but getting it off again intact, to transplant? Forget it!
 

Owen Smith

Active Member
Ooohhh... a ball grid array, huh! Pretty bloody tricky. Not too bad to assemble in the first place (with production tools), but getting it off again intact, to transplant? Forget it!

There are companies that can do it with high reliability. But it's not cheap. At my previous employer we occasionally paid to have big BGAs like this one moved between boards, for testing that a new version of a chip (because the old one had gone obsolete) worked in existing designs and vice versa. One of the problems having removed a BGA is it has to be re-balled before it can be soldered onto another board. We usually paid to have 5 boards done, and expected to get 4 boards back that worked. Sometimes all 5 worked.
 

Owen Smith

Active Member
You call 80% success "high reliability"?

Compared to one out of five working at best when we tried to do it ourselves, yes 80% success is high reliability. The cost saving of trashing one board is enormous when you get four working production boards with a different chip on it. It's way cheaper and a lot quicker than having five boards made specially from scratch with non standard chips on them. Bear in mind in a prototype/development environment all of these boards will ultimately be thrown away anyway. We were spending hundreds of pounds to save thousands.
 
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