recovering hard drives information

[Hyperspeed]

I would vote the Dyson vacuum cleaner my 2nd favourite piece of design below the Amiga. Beautifully thought out and with a dust filtration of 99.97% it is almost good enough for microchip fabrication plants let alone for those with asthma.

I read somewhere that someone's hard disk bearings had seized so they put the thing in the oven - unseizing the bearings so that data could be recovered!

Bare in mind though that if ever anyone has data that is so precious they simply must have it (and can afford the money) a lot of labs not only offer an engineering solution to your data recovery but also a forensic solution - magnetic hysteresis can recover data on a platter that has been Full Formatted 20 times...

[Oliver]

I use a dyson too.  Damn good.

Heating definitely can work, but I would try freezing first.

[amigaoneproductions]

Oliver wrote:
I use a dyson too.  Damn good.

Heating definitely can work, but I would try freezing first.

Agreed,  Dysons SUCK !

[motrucker]

Hyperspeed wrote:
....Now consider the fact that each square millimetre on a hard disk platter could be responsible for 10MB of data, moreso if you consider the way data is laid out in clusters etc. then you are taking a serious risk by opening up the disk. One speck of 0.3micron dust potentially cause a bad block or something!
:-) :-) :-)

I did not offer this idea as a fix, but a way to reteive the info on the drive. It really does work. BTW, I live with two young kids and dog who sheds canstantly.
How do you think the pros do this? same way (granted they usae a clean room).
This IS a last resort! but it works nore often than not.

[Hyperspeed]

I'm not disputing it'll work, in fact I might go on eBay and look for spare drives identical to mine should I ever hear that ping-pong sound of a bearing failure.

I did read about something in some disk drives to do with air pressure and venting, I wonder if hard disks have their own air purification filters?

Anyway, good luck finding the animation. I found an old animation in my disk box recently made with Deluxe Paint 4 AGA... never worked out how to add sound to coordinate with the frames...

:-)

[amigaoneproductions]

Hyperspeed wrote:
I wonder if hard disks have their own air purification filters?

Yes they do,  well,  nothing that looks high-tech,  it's a fine paper / cloth filter,  have you ever seen on a hard drive's casing "Do not cover this hole" - That's the hard drive breather hole, under which is the air filter.
There's usually a small sachet of silica gel hidden inside as well to absorb any moisture that does get in there.

I have stripped down several hard drives,  if you are careful, you can do all of the above without a clean room.  Eating a jam sandwich or a sticky toffee pudding while working on a hard drive is not really recommended ;-) ,  but all of this can be done,  all this talk of having to send a hard drive to a high cost lab is utter nonsense.

These are the facts (As written by me,  a computer engineer who has been doing this stuff for the last 18 years :-) )

If the hard drive is spinning and being recognised by the OS,  then software recovery tools will usually get the job done.

If the drive is not spinning or seen at all, i.e. not even at the lowest level then you have a more serious fault which will probably mean getting out your screwdrivers.

If the PCB is the cause of the fault,  which is the most likely - it's the most complicated part of the system,  changing it with an IDENTICAL (same revision, same firmware) one will solve your problem.

If you still need to go further,  then changing the head assembly (if the drive is spinning, this is the easiest bit to do)  or moving the platters across to another drive is all perfectly possible.

Lots of people seem to be guessing at what is possible and what is not,  believe me,  all of the above is possible to do with some very basic tools,   I've probably not covered all the different possibilities here,  

It's all a myth,  probably created by the same people who tell me I can't replace surface mount components with a standard soldering iron,  hmm,  so this is not a DMA fixed AmigaOne I have here is it then,  must be a figment of my imagination.  

All this comes down to knowledge of what is needed to be done,  special tools,  expensive clean rooms,  all a big money making con
 :-)

[Hyperspeed]

One thing I had considered though is this - when HDToolBox maps out a bad block or low level formats a hard disk, is this updated information stored somewhere on the platter or in the drive's logic?

If it's stored on the board then wouldn't replacing the platters be lethal?

Also, don't you really have to make sure you put the platters back in the right order? I imagine this would be for the very brave, no good leaving the room and coming back after forgetting what goes where!

It's reassuring what you say though, maybe we should all make a point of not only backing up our software - but backing up our hardware!

Race ya to eBay!

[amigaoneproductions]

when HDToolBox maps out a bad block or low level formats a hard disk, is this updated information stored somewhere on the platter or in the drive's logic?

It is saved as a file on the hard drive,  I can't remember if it was HDToolBox or QBTools,  but one of them creates a file called bad.blocks, that file just uses those bad blocks so nothing else will try and write to them.

As for bad blocks that you never get to know about,  i.e. those that the drive maps out automatically,  thats a different story.  All drives have defects,  older drives used to have the defect list printed on them, and you would need to enter this list into your formatting software to tell it not to use those areas, but new drives do this internally and try to present themselves to the OS as perfect disks by automatically remapping spare blocks.  Only when it can no longer do this will the drive actually admit to you that it has a problem.
As for where this information is stored,  I am not sure if it's platters or logic,  anyone else know that bit ?
(I know a lot about how this stuff works,  but I don't know everything ;-) )

[Hyperspeed]

I have a tool I keep in the Expansion directory called 'Probe SCSI':
ftp://de.aminet.net/pub/aminet/disk/misc/ProbeSCSI008.lha

If you type in the CLI - probescsi 0 (or whatever unit your hard disk is on) then at the bottom of the readout it will display a 'Primary Defects List' and a 'Grown Defects List'.

I swapped my old hard disk when I saw the 'Grown Defects' had increased since I bought it, I'm just wondering if this is the drive's own intelligience mapping out the bad blocks... wonder if flash drives do the same (I've heard compact flash cards do since they're prone to a limited number of write cycles).

[Will-i-am]

Hyperspeed wrote:

Anyway, good luck finding the animation. I found an old animation in my disk box recently made with Deluxe Paint 4 AGA... never worked out how to add sound to coordinate with the frames...

:-)

Re the sound thing, there's an old great animation editor called Animation Station that I used on my A2000s and it was the easiest thing you ever saw for coordinating sound to frames. I've seen other programs where you essentially write a script and that works great but AS was (and still is) so simple. Each frame could be called up as a single image on the screen with a list of things relating to that frame. So a particular sound or text or voice, could be hooked to that event. It always worked, was dirt simple to change and the only complaint I ever had with it was when I upgraded to 3.1 with my A4000D. Then it broke.

There was also this ancient program, shareware of course, I think it was German, had a funny name like "M" or some such thing.... but it was similar in set up but the thing that amazed me was not only how each frame could carry various events like sound file start and sound file end... so the sound was stretched over the frames in between, but it could play huge animations very very fast. I tried a multi-hundred  frame 2 color anim, just shadows on a white background and it was shooting em on the screen at about 60fps for the smoothest anims. I think Animation Station evolved into Anim Workshop, which I acquired in a garage sale awhile back only to find that it requires a keyfile to run and the company has since folded (of course). So if anybody has said keyfile around I would be exceptionally happy to trade for it.

[metalman]

amigaoneproductions wrote:

If the hard drive is spinning and being recognised by the OS,  then software recovery tools will usually get the job done.

If the drive is not spinning or seen at all, i.e. not even at the lowest level then you have a more serious fault which will probably mean getting out your screwdrivers.

If the PCB is the cause of the fault,  which is the most likely - it's the most complicated part of the system,  changing it with an IDENTICAL (same revision, same firmware) one will solve your problem.
 
 :-)

I've repaired several harddrives by swapping the drives PCB controller board. Had to watch ebay for 4 months once to find an identical one...    

I would guess the most common failure of the PCB (any PCB) would be one of the electrolitic capacitors drying out. Try replacing all the electrolitic capacitors on the PCB board if you can't find an identical one, Try the ones closest to the motor start transistor first, since the drive does not spin up.

Would not open up the drive unless you heard it was making noise before failure!