Hi everybody,

Any successful experience in platters exchange rather than head stack exchange and want to share the experience here ?
I am getting a couple of scrap HDDs to make some experiments, but before wasting time I wish I could hear some experience from other people.
According to my knowledge, probably swapping the platters in case of HSA failure could lead to success in recovering the data - but is only theory.
The unique "incognita" could be the adaptive parameters for the HSA , I think those parameters are more important for WRITING (i.e. calibration of the magnetization current especially for MR heads) rather than for reading data, just because the decoder has PLLs and - hopefully - AGC. The digital signal processing usually adopted as decoding technique could do the rest.
Some people said that a major issue in platter swapping could be the micrometric shifting of the platters, but... the SERVO in this case won't help ? And what about the thermal dilatation in the metal surfaces / bearing / rotor when the drive is operational ?
Other people said that head switching won't work because it is impossibile to put the platters in the exact position in order to have the surfaces switched right on time ; in that case, I think that the decoder , even if after switching does not find the right header, should read "right" at the next passage after one revolution of the platter - while the servo keeps the head right on track.
The trouble is just working on clean room and with ANTIMAGNETIC tools (ceramic screwdrivers etc.) because the magnetic field (even weak) of a common screwdriver could destroy servo/data on the platters, and also work on static-free environment as could damage circuitry and destroy data on the platter (but anyway I work with hitech equipment and electronics and I have never damaged even static sensitive devices like RF MOSfets or MOS ICs with nothing but common precautions - electronic devices are self protected and more solid and robust than we imagine)
What do you think ?
Regards.

Changing of Platters is no solution only head could be changed.

1 if one Platter (i dont think so)

2 if more then 1 Platters they cannot be reAligned.

Only head could be changed as it could be Aligned for reading SA from HDD

DF

Hi,

I am looking for a cheap solution to make a clean room.

Is there any suggestions?

Thanks in advance.

Baha Cevik

The cheaper solution is "not to make a whole room " clean... and anyway the purpose is to have sufficient cleanliness for opening the equipment, work, get data back and then the drive should be discarded anyway.
A good solution is cleaning the drive externally with alcohol and lint-free cloth (easily available on the market as laboratory material) and compressed air, then work on a closed cap / cabinet that could be easily cleaned . I was working on a home-made solution made with perspex and self-vented , the only critical element is the filter, is very difficult to find small quantities (and anyway this is not definitely cheap) of filtering material - the same used on air filtering of the class 100 or 1000 clean rooms.
Also, I should consider keeping the dust down using ionization, but the risk is to build some static charge....
BTW... about 13 years ago, I repaired some HDDs opening the case for mechanical repair under a light jet of compressed , filtered air... and relying on the internal filter of the HDD that should capture the "remaining" dust.... believe it or not, those drives worked for years - I recovered the data and gave them back to the owner telling him NOT TO USE them for work but only as a scratch or for more experiments. They were just 40 MB (yes, megabytes) or so, but it worked.
I remember that a guy, in the early 90's, decided to repair his ST125 , a 5"1/4 20 MB HD by itself beacuse of the cost of a new HDD.... the drive didn't spin up but applying power you could hear the motor trying to start. He opened the top cover not caring for cleanliness and the dust on the equipment, put some oil (!) and then the seized platter assemby was able to spin again. Incredibly, this drive booted, and stored and retrieved data and kept working .... I don't know for how much time.... but sufficient for making a backup copy of the data.

Regards

Dear BlackST

Thanks for your reply.

There is a vacuum cleaner which filters the air with water, so all the dust stick on water and the air become dust free. What do you think about that, will it work? http://www.rainbowsystem.com/eng/ is the link of the vacuum. I have one in my home and no filter needed since you use water as a filter.

Baha Cevik