Problems with panasonic dmr ex75 HDD recorder

Deano 19690

Novice Member
Hi All,
I'm new to the forums and in need of some advice/help.
Having owned several panasonic hdd/DVD recorders over the years I know all to well the problems of the U81 and No freeview tuner problems.
Steve on ebay has fixed a few for me in the past.
Now when one of our machines just died the other day with the missus dvd disc inside. I opened it up to see the power board looking a bit worse for wear.
So then I purchased another machine off EBay , real cheap with a U81 fault and removed the power board to use as a donor for the faulty one....
It worked, i released the disc, dvd and hard drive still working as before.
All good so far.

However, me being a nosey sod then decided to swap over the HDD drives to see what was on the donor machine.
After turning the power on it greeted me with a 'Format HDD ' screen and No other options.
Not knowing what state the donor hdd was in, I did so. It formatted ok and I recorded on to it.
The problem came when reinstalling our original hdd back in, again i am greeted with a 'format HDD' screen.,
no other options...
Now we had recordings of the kids/holidays etc on there that I really don't want to lose.
I thought it would be a simple plug and play hdd like the external hard drive we connect to our laptops .

If anyone can advise me how to reconnect and save our recordings I'd be grateful
 

jonoro

Active Member
Without a tremendous amount of work your recordings are lost.
There is a requirement imposed by the tv and film industry, that hdd recordings are tied to the recorder and can not be copied or played on other machines. This is acheived by tying the hdd to the recorder. Panasonic tie the hdd to the power board, hence it demanding a format, to effectively delete all recordings.

You will likely be able to recover snippets of recordings but with no recording names and no idea which snippets belong to which and no idea of the order is either, you would face a tremendous challenge.
 

jwillis84

Standard Member
The problem your describing makes perfect sense, based on the order of events.

Panasonic recorders after the 85H model here in the United States began including a "transaction number" that rolls forward after each change to the hard disk and storing that in the non-volatile memory on the mainboard and the hard drive itself.

On power up the recorder compares the "last transaction number" held in NVRAM to the value stored on the hard disk. This is used to detect corruption or differences on the hard drive.

When they don't match the recorder goes into auto-repair mode and attempts to "fix" the hard drive by suggesting it be re-initialized, wiping the hard drive of its recordings.

I believe its called a "uformat fault". If it succeeds then the drive is reset and allows you to continue making new recordings.. but the old "transaction number is wiped or lost" so putting the old hard drive back into the recorder will result in a new "mismatch" and it will suggest re-initializing it, also wiping it of its recordings.

The solution depends on whether you allowed it to "re-initialize" or wipe the original hard drive.

Basically I can describe what needs to be done to save the recordings and to restore the hard drive so that it matches the recorder again.. but neither will seem easy.. and require technical skill.

The fairly good news, is Isobuster can probably read and copy the recordings from the original hard drive and put them on a PC. (If the hard drive hasn't been wiped).

The software costs money to actually copy the recordings, but you can run it in demo mode to see if the recordings are still there.

Now as to re-synchronizing the "transaction number".. I have not worked out a minute carefully scripted procedure.. but it goes roughly like this:

The transaction number is stored in the area of the hard disk "before" the recordings index on the drive. To learn this I have to use a hex editor and scan for a few keywords in one of the recordings title. The areas of the hard disk are separated by gaps of empty space.. so once you know where the recordings index table is.. you can back up until you find yourself in an empty area of the disc.. usually filled with zeros.

So now that you know how many bytes for this particular model you need, you can use a different hard disk to wipe and initialize in the recorder.. copy just that number of bytes from the newly initialized hard drive and put those on the old hard drive.. with the new "transaction number" that is currently in the recorder.. with luck.. when it powers up they will match.. and your recordings will show up again and can be played.

Any previous scheduling or electronic program guide information will be gone.. so if you had a season pass.. or a schedule to record upcoming broadcasts.. those will all be gone.. since the initialization did not carry over from the old drive to the new drive.

This procedure could be vastly refined and formalized.. but the Panasonic repair depots never offered a service to recover user recordings or perform service on customer hard drives.. the standing procedure was to wipe the drive, or replace it and tell the customer it was not possible to recover old recordings. -- there are myriad reasons for this, from protecting the customers privacy, to avoiding copyright claim entanglements.. and downright costs associated with recovery time.. and customer dissatisfaction if the repair did not go right.

The most important thing you should do however is safe guard the original hard drive and make sure its labeled with a sticky note or something so it doesn't get used for something else, or accidentally get wiped. The next thing is a technical person should make a backup of it using a raw disk imaging tool like Hdd Raw Copy Tool 1.10, or Isobuster (it has an image backup feature).

Then you can feel safe going about the task of recovering the recordings to a PC, and or re-synchronizing the original drive to the NVRAM so you can use it as before.

My experience is people tend to get very emotional and keep trying things until they damage the situation beyond hope.. and or wipe the drive and then there is nothing you can do.. you could then "try" to see if something like Isobuster can scan the entire hard disk and try to pull off videos.. but its much less likely to work. The recorder index table contains information that tells Isobuster where recordings begin and end and how long they are in logical blocks.. which enables it to be much more precise.

I went into a lot of detail not knowing where you are at in the process at the moment.. because other people might get into the same situation and think it was hopeless.. in the beginning.. before thrashing back and forth and doing desperate things.. it really isn't.. but after a few hours or days.. it tends to become hopeless.

Back tracking a bit.

An event that updates the "transaction number" by rolling it forward includes many possibilities, it can be a new recording being made, changing a setting in the recorder menus with the remote or buttons on the front of the recorder.. or a simple update of the electronic program data with a new scheduled program to record. Any of these can cause the "transaction number" to update.

The non-volatile memory and the hard drive aren't normally updated simply by inserting a different hard drive into the recorder and powering up.. it was that "format" that was performed in the attempt to see if anything was on the other recorders hard drive that did the trick. That's what rolled the "transaction number" forwards.

I don't know what Panasonic officially calls it, I call it the "transaction number" simply because it reminds me of the transaction log of a database, or at least that is how it behaves.

Now something else you should be wary of is after CPRM, the hard drive serial number was used to create an encryption key when it was initialized and stored on the hard drive as well.. specifically so that you "could not" play back recordings marked by the broadcaster on any other recorder.. this was due to a requirement to satisfy Copyright Laws. Not all broadcasts carry the CGMS flag that tells the recorder to encrypt.. but the encryption key is generated and it can only be decrypted from the hard drive with the original serial number.

So cloning the drive and restoring the transaction log will play back all un-encrypted recordings.. which if they are all personal camcorder footage they should be un-flagged and thus un-encrypted.. but I bring it up, because after being burned by previous events.. people sometimes try to safeguard by only working with a cloned hard drive.. and the serial numbers won't match up.

This also leads to any DVDs burned of "flagged" recordings also being encrypted and "tied to the recorder" so that they will only playback on the original recorder that made the original recordings.. all kinds of surprising Copyright inventions show up when you least expect them.. the thought process there being most people won't try to playback recordings on other DVD players.. and any video given to relatives on DVD should be personal camcorder footage which isn't encrypted. People only notice when the recorder dies.. and assume the DVD has gone bad since it won't play back on the new DVD recorder they bought.

To be sure.. you ("should") make a full raw disk image backup of the hard drive on another hard drive to work from.. and keep it safe. Isobuster can work with a raw disk image in fact... and need never touch the original hard drive.

But when it comes to trying to re-sychronize the hard drive with mainboard memory, its best to work with the original hard drive.

And its best to be very aware of how your Panasonic indicates to you that a recordings has been Copy Protected.. with an icon, or CP or some other indicator in the title menus.. so you know those are at risk.. and any DVD's made of those.. will be tied to the life time of the hard drive they came from.. and possibly the recorder if the hard drive dies with it.
 
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Deano 19690

Novice Member
Thanks for your input , that's far more then a layman like me can comprehend.
But someone has previously mentioned to me..
"it can be done by using a clone disc or drive but it's complicated"
So I know we're on the right track here.

So you say, unplugging the hard drive and reconnecting it didn't cause the problem.
The problem was caused by reformatted another hard drive on the same machine?
Is that right ?

I'll have to ponder the rest of the info...

Thanks for your input though, its very appreciated 😀

I never got notification of your reply other wise I woukd have been back here sooner
 

Chris pat

Novice Member
Hi I have being trying to set up my Freeview Panasonic DVD recorder,it recorders from the Hard Drive ,but it will not tune in from the Arial,there is nothing wrong with the Arial, because I works with the TV,as soon you go to settings the set up goes from the left hand side to the write hand sid,but with no channels,I have got three the same modal Neither will tune in can you try to help me,there yous to tune in,but I do not why this has happened,thanks.
 

Deano 19690

Novice Member
Sounds as though the built in digital(freeview) tuner has failed .
This is a well known fault on these machines and has happened to several of mine.
Some capacitors or something will need replacing on the circuit board and it will all need resolderng in .
The other well known fault is the error message U81 . Again this needs new parts resolderng in.
 

Chris pat

Novice Member
Hi I got a problem with my DMR-EX 75 Freeview dvd recorder,I do not no why it will not Auto set up on restart,with Freeview channels,but the Arial led is the same for my TV,but I got three Arials adapters to the out side Arial,i got 3 Freeview Dvd recorders,and no of them will not tune into eny channels,but there youse to I can not figure this out,do you think I my have to get another Hard Drive Freeview DVD Recorder.
 

Chris pat

Novice Member
Hi I got a problem with my Panosonic DMR-EX 75 Freeview recorders there will not Auto set up on restart,with my Freeview channels,but the Ariel led works with my TV,I got three Adapters for the out side Arial,so you can put the Arial LEDs in,but I can not under stand why there will not tune in.thanks
 

Videoverboard

Novice Member
Without a tremendous amount of work your recordings are lost.
There is a requirement imposed by the tv and film industry, that hdd recordings are tied to the recorder and can not be copied or played on other machines. This is acheived by tying the hdd to the recorder. Panasonic tie the hdd to the power board, hence it demanding a format, to effectively delete all recordings.

You will likely be able to recover snippets of recordings but with no recording names and no idea which snippets belong to which and no idea of the order is either, you would face a tremendous challenge.
I have a similar problem with a Panasonic recorder (a DMR-BWT850EB in my case) which won’t start up properly and I suspect it to be due to a faulty power board (SEP0617A) which I was hoping to swap with the same board from a donor machine to see if it fixes the problem. I notice you said that “Panasonic tie the hdd to the power board” but member Chris pat had stated that the donor power board fixed the original problem and all was working OK again until he then tried swapping over the HDD, at which point he found he needed to format it and it became the HDD tied to the machine, jeopardising the content of his original HDD because it could only become usable again by formatting it to re-tie it to the machine.
The point of clarification I am seeking is about what the HDD is actually tied to. You said the powerboard but the detailed explanation provided by member jwillis84 indicated that the tie was made via a record, I.e. “transaction number” on the hard disk and then storing that in the non-volatile memory on the mainboard and the hard drive itself. I am wondering if the mainboard is the green one with the controller circuitry rather than the brown power board.
Any advice that you or any other members could provide would be appreciated. Thanks.
 

jonoro

Active Member
I can state categorically that with a BWT720, and I expect the 850 to be the same, if you swap the power board then the unit will demand a reformat of the HDD. I have tried this out at least 5 times with the same result each time. Looking at the circuit diagram there is an 8 pin EEPROM mounted on the foil side. This is an orphan there in that all its pins are directly connected to the power board's connector and not to any components on the board. Furthermore I have read the contents of the EEPROM before and after a HDD swap and can see the changes.

I should point out that Panasonic name the board with the power supply on it the "Main" hoard. Confusing. (I always use "power" board as the name) They do not use the term "power" board.
Their name for the board with the vast majority of components is "Digital" board.

What I have not tried is a swap of the digital board to see if that results in a format demand. It may be that it is not only the HDD & power board that are tied together but that the digital board is tied too.

I think that once a different HDD or power board has been connected and powered up then even if a format has not been carried out you can not just put the old HDD or power board, you will have to reformat.
 

Videoverboard

Novice Member
Thanks for your prompt reply. It's good to be aware of these constraints before attempting any "swap over" repairs that could ultimately render the unit unusable without a reformat of the hard drive and resultant loss of recordings.
 

jonoro

Active Member
Just to confirm what I advised - the folloing taken from the service manual:
"Service Navigation 3.1.1. How to format for HDD when replacement of HDD or Main P.C.B."
and
"Notice after replacing Digital P.C.B. or BD Drive Formatting the HDD is unnecessary after replacing Digital P.C.B. or BD Drive."

Remember the big PCB with the heart of the unit is called "Digital PCB" by Panasonic and the "L" shaped PCB is called "Main PCB" by Panasonic
I hope this further allays any worries you might have about loosing recordings when changing components.
 

Australopithecus

Standard Member
Thanks for your input , that's far more then a layman like me can comprehend.
But someone has previously mentioned to me..
"it can be done by using a clone disc or drive but it's complicated"
So I know we're on the right track here.

So you say, unplugging the hard drive and reconnecting it didn't cause the problem.
The problem was caused by reformatted another hard drive on the same machine?
Is that right ?

I'll have to ponder the rest of the info...

Thanks for your input though, its very appreciated 😀

I never got notification of your reply other wise I woukd have been back here sooner
I feel your pain. I almost lost the contents of an HDD when trying to swap an HDD from a machine that had a RAM drive failure to an identical second-hand recipient machine with a working RAM drive. I fortunately stopped short of formatting the disc and consulted my son who is versed in these things. What we did is documented in the thread "Restoration of Panasonic DMR EX78" in this forum.
 

jonoro

Active Member
This query was about the BWT850 which I believe has the EEPROM on the power supply board. I don't believe that the EX series had this.
 

jonoro

Active Member
Mod
You might consider splitting this thread as the title is misleading now.
It has moved from the EX series to the BWT one and they are different beasts.
 

pevers3

Standard Member
This is more like in a computer in which if you change tithe motherboard programs tied to that particular board are lost, has anyone come up with a solution to this, has anyone tried using the dual docking station, Without a tremendous amount of work your recordings are lost.
There is a requirement imposed by the tv and film industry, that hdd recordings are tied to the recorder and can not be copied or played on other machines. This is acheived by tying the hdd to the recorder. Panasonic tie the hdd to the power board, hence it demanding a format, to effectively delete all recordings.

You will likely be able to recover snippets of recordings but with no recording names and no idea which snippets belong to which and no idea of the order is either, you would face a tremendous challenge.
 

pevers3

Standard Member
Without a tremendous amount of work your recordings are lost.
There is a requirement imposed by the tv and film industry, that hdd recordings are tied to the recorder and can not be copied or played on other machines. This is acheived by tying the hdd to the recorder. Panasonic tie the hdd to the power board, hence it demanding a format, to effectively delete all recordings.

You will likely be able to recover snippets of recordings but with no recording names and no idea which snippets belong to which and no idea of the order is either, you would face a tremendous challenge.
Hi, Resd you descripyioneiyhninterest you deem to know a lot about these Panasonic machine, is there a solution to
Mine, whereas I can convert video from a pc via software and burn this to a dvd-r:-re or dvd ram and also vopy the contents onto its hard drive but when it come to blu ray whilst come programs will burn to a blu ray disc which is either rrvonihex and will play it it I’d not recognised but not one will copy to its hard drive meaning if you have say several small video on a25gb bdisc with the remainder unavailable which makes the method ridiculous, is there a way round this as it seems down yo what format is finally used or is it another repeat of yours where then blu ray is tied to the Panasonic hard drive
 

jonoro

Active Member
Not sure what you are asking but you can copy recordings made elsewhere on a pc say to the HDD of a Panasonic BWT720. These can be in hd or sd.
Rather than transfer via a recordable disc using a USB memory stick would be easier. Page 70 of the manual refers.
Note hd must be in AVCHD encapsulation and sc in mpeg2.
I would expect, but have not checked, that once the recordings were on the HDD they would be tied to that recorder if hd.
 

pevers3

Standard Member
Hi All,
I'm new to the forums and in need of some advice/help.
Having owned several panasonic hdd/DVD recorders over the years I know all to well the problems of the U81 and No freeview tuner problems.
Steve on ebay has fixed a few for me in the past.
Now when one of our machines just died the other day with the missus dvd disc inside. I opened it up to see the power board looking a bit worse for wear.
So then I purchased another machine off EBay , real cheap with a U81 fault and removed the power board to use as a donor for the faulty one....
It worked, i released the disc, dvd and hard drive still working as before.
All good so far.

However, me being a nosey sod then decided to swap over the HDD drives to see what was on the donor machine.
After turning the power on it greeted me with a 'Format HDD ' screen and No other options.
Not knowing what state the donor hdd was in, I did so. It formatted ok and I recorded on to it.
The problem came when reinstalling our original hdd back in, again i am greeted with a 'format HDD' screen.,
no other options...
Now we had recordings of the kids/holidays etc on there that I really don't want to lose.
I thought it would be a simple plug and play hdd like the external hard drive we connect to our laptops .

If anyone can advise me how to reconnect and save our recordings I'd be grateful
Hi. Is this similar to how sky tie the hard drive down so you cannot swap a hard drive for a bigger one? but then you cannot even use the usb with a caddy as this means again re-registering the drive again which immediately formats it. How involved is your method ad ther is a way to get recording from sky disc with software via a computer I have heard but never tried, a guy on YouTube explained ss the particular file format had to be altered.Again this explains why I am able to record to a blu ray which will play in both the drive and computer but if this is genersted via the computer the recorder will play it fine but refused to copy/move the contents to the internal hard drive, defeating the object of using blu ray discs capacity, the computer generated dvd will both play and copy ok, tried this with a ram disc but it was a complete failure turning this disc into a beer mat
 

Australopithecus

Standard Member
It is possible to save your precious recordings. The method used is documented in a thread entitled "Restoration of Panasonic DMR EX78" on this forum. The procedure involves the use of Linux operating system, but was quick and effective. I think that the method applies to all models of a similar era at least and possible to all models anyway. Good luck.
 

pevers3

Standard Member
Not sure what you are asking but you can copy recordings made elsewhere on a pc say to the HDD of a Panasonic BWT720. These can be in hd or sd.
Rather than transfer via a recordable disc using a USB memory stick would be easier. Page 70 of the manual refers.
Note hd must be in AVCHD encapsulation and sc in mpeg2.
I would expect, but have not checked, that once the recordings were on the HDD they would be tied to that recorder if hd.

Hi, What J am asking is when I record video converted via different computer software which will then burn to a BD-R or a BD-RE the blu ray disc will usually be playable on the Panasonic but will not copy its contents to the machines hard drive unlike say a dvd-r or -rw, I have tried numerous video converter software which state blu ray as the file type but as it not viable to record 2gb on a say 25gb blu ray disc and then this is stuck on the disc Leaving k et 20gb spare but unusable, My normal course if action was to convert in the computer burn to a dvd-rw disc then copy to the hard drive in the Panasonic then format the dvd again, is this clearer to you
 
Last edited by a moderator:

jonoro

Active Member
Yes I now understand.
Please be aware I am talking about BWT720but this thread refers to EX76, a vrty different machine.
But why copy to BD at all? Why not a USB stick as I said. Or SDXC cards in which case upto 64Gb if using exFAT? Much easier and quicker than vopying to discs.
 

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