Although some CCTV hard drives can be based on a standardized Operating system, many are not. In law enforcement there is an entire subset of digital forensics dedicated to Video Evidence from sources like this. A good resource for training in this area is LEVA International. A great program for reading and extracting data from proprietary DVR drives is DVR Examiner by DME Forensics. They even offer a free trial of their software to verify it can access and read the data on your drive before you buy.
I had tried DVR Examiner, the problem was though, that the drives wouldn't image/read (unless powered by the original system in the first instance), so was curious as to the reason why (if anyone had an idea).
So, whilst DVR Examiner is a useful tool for processing the unusual file-systems, and exporting data from them, that's not an option if the drive can't be read!
Still none the wiser, but I've worked round the problem(s) for now, but would always be interested to hear if someone has had similar experiences with CCTV drives.
Some CCTV systems use an ATA lock on the drives so they can't be read outside the DVR. They could also be using PUIS (power up in standby mode). There's a few reasons.
Depending on the drive model, there's sometimes free utilities to unlock it (for example WD usually has a generic master key for ATA lock). Other times, it requires tools like PC-3000 to override the function and get the drive working normally.
Either way, a reputable data recovery company should have no problem unlocking and imaging such drives.
I would measure the voltage output of the computer's power supply with a regular drive connected and then the DVR drive connected. If there is a measurable difference, it might be simply a bad connection.
Used (old) power supplies aren't giving the power needed to spin up the drive if oxidation or other corrosion appear on the power pins.
…or just simply connect the DVR drive to another computer.
I would measure the voltage output of the computer's power supply with a regular drive connected and then the DVR drive connected. If there is a measurable difference, it might be simply a bad connection.
Used (old) power supplies aren't giving the power needed to spin up the drive if oxidation or other corrosion appear on the power pins.
You sure it would be a (measurable) voltage issue, and not a power (Amperes) one, as JaredDM previously mentioned?
For sure once upon a time external 2.5" external cases came often with a (needed) USB Y cable as taking the power from a single USB port (500 mA) was not enough for many (old) 2.5" drives.
Voltage was obvioulsy 5 Volts allright, but simplt not enough Amperes could be drawn to spin up and operate the drive.
And it happened to me more than once that a (old) power supply gave the right voltage but not enough "juice".
jaclaz
@jaclaz no, as I wrote, voltage!
I fully understand what you are trying to say with the power consumption and milli Ampers given / taken, but if the voltage will significantly vary and not stay constant, it means there is a capacitance issue + heating, which usually is caused by bad connection / corrosion / oxidation.
@jaclaz no, as I wrote, voltage!
I fully understand what you are trying to say with the power consumption and milli Ampers given / taken, but if the voltage will significantly vary and not stay constant, it means there is a capacitance issue + heating, which usually is caused by bad connection / corrosion / oxidation.
Let us agree to disagree. )
In my little experience it varies greatly on the specific power supply (and the EXACT way it is regulated), anyway bad connection/corrosion/oxidation has nothing to do with capacitance issues (that are usually due to failed or failing capacitors, particularly electrolytic ones if old or underspecs) .
When there are issues with bad connections/oxidation, very rarely there is a lowered voltage, it is more likely that the oxidation completely insulates the connection or - like it is often the case with cold soldering - the connection is intermittent.
jaclaz
Interesting replies. I don't believe it was an ATA lock.
Haven't got the drive to check now but off the top of my head when I've had those drives they sounded "fine" but simply failed when trying to read data (not sure about this - but if I remember rightly they still "present themselves" as a drive but just fail to read).
In this instance I'm not even sure it got that far and sounded "lethargic" is the best way to describe it.
So the power issue would have seemed more likely, but I did try powering it via a tableau, and directly via the system, and via a dock, none of which worked, so seems unlikely to be the power systems/connectors I was using.
I suppose the PUIS is possible, can't check now as I say, I wouldn't exactly have expected it to quite sound as it did - if it's that, as presumably it would be more silent, but perhaps not.
I'll probably never find out the answer (as the job is done now)!
jaclaz - I guess it's all part of the "fun" of the job. Many years ago I once had a drive that wouldn't image for love nor money via ATA66/ATA100 cables. After trying the usual swapping cables (and everything), just in case of a defect, I finally tried an older ATA33 (40 pin) cable…and hey presto it worked. Not being an electrical/cable expert I've no idea why it worked (as I thought the higher cables just had an extra 40 set of wires for grounding/shielding)…but it did.
jaclaz - I guess it's all part of the "fun" of the job. Many years ago I once had a drive that wouldn't image for love nor money via ATA66/ATA100 cables. After trying the usual swapping cables (and everything), just in case of a defect, I finally tried an older ATA33 (40 pin) cable…and hey presto it worked. Not being an electrical/cable expert I've no idea why it worked (as I thought the higher cables just had an extra 40 set of wires for grounding/shielding)…but it did.
Sure it is )
I must still have somewhere an ATA drive, 20 or 40 GB, that seemingly worked fine in reading, but could not write a single byte position, after endless hours it came out that one of the pin solder was a cold one, and *somehow* (don't ask for any rationale reason) had become a sort of diode, allowing data to flow only in one direction.
The one you just cited was probably in the times where both cable select and 80 pin cables came out, the culprit in that case would be either pin 28 or 34 (I would bet on 28).
jaclaz