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Clear Hard Drive Mods
Baloo Ursidae writes "In the spirit of the case window kit and the clear PC case, there are people who have made hard drive windows, and apparently they're not alone."
That ladies and gentlemen, takes balls.
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Opening a hard drive lets in dust that will cause a catastrophic failure after a while.
The owls are not what they seem
if I'm not mistaken, it was the good ole RLL harddrives (before IDE, heh)
I think it was runnin Windows 3.1 :)
You're creating a Farraday Cage, where any energy that goes out hits a piece of metal, gets absorbed, then goes to ground and out. The metal tabs along the edges prevent any waves that are in the same phase as the opening from leaving. So by putting metal tabs along a non-conductive material will help, but not much. The waves will still pass right through the material and out.
I used to do FCC and UL testing of PCs, so ran into this often.
Noone is suggesting that you do this your mission critical brand new 160GB drive. I did this to a 2gig (and submitted the details to Overclockers.com weeks before they posted their version, but they never posted mine. Punks!) and I use it as a swap drive. Yes, you would be a moron to do it to your only system drive, but if you have a spare or two laying around its a nifty little mod. Also, the RF noise everyone is yelling about thus far has not been a problem at all. What about all the unshielded magnetic fields your 10 case fans are generating?
"A coward dies a thousand deaths, the brave but one."
As a former hard drive engineer for IBM, I can aboslutely tell you that if you do this mod your hard drive will not last long.
The case is nearly sealed-- the only opening is for pressure equalization and is protected by a pretty advanced catacomb filter. Drives are assembled in clean rooms to minimze the internal particle count after manufacture. Remember that the distance between the (moving) head and the (spinning) media is measured in nanometers!
Why does a hard drive stop working when it takes a shock, sometimes not when the shock happens but a few hours/days/weeks later? It's becuase the heads slapped into the media, chipping off some of the magnetic material. That doesn't immediately kill it-- the disk automatically notices that it can't write those bits anymore, and reassigns them to one of the spare areas. It's the little bits of magnetic material floating around the drive that kill it. Eventually, they find their way to one of the heads and block it from reading/writing. Or, more spectacularly (and more rare) if the debris is big enough, it will wedge in between the head and the media and score the substrate (aluminum or glass), which sounds a little bit like a turbine exploding.
Hard drives are incredibly complex and sensitive devices. Unless you also think it would be cool to crack open your processor case and put a little window on it-- don't do your hard drive. Now, if you have a hard drive you don't need, you can add the window to make it look cool, but don't expect it to work. Also, it's unlikely the arms will move much, so just expect to see the platters spinning.
I opened my 40MB Amiga hard drive several years ago. Cover off, look inside and put the cover back on. The drive got fucked up in two months.
Besides, why would the companies invest millions in clean room fab space if the requirement bogus Tha's the financial argument. If that doesn't convince you, you can check out the physics. A particle you can see with your bare eyes will not fit under a modern GMR head and the platter.
The owls are not what they seem
You're cutting the top peice far from the body and spindles of the drive, foo, nothing falls into the drive. As for the plastic wrap idea, I found its better to put it first in a static proof bag and then into a ziploc bag. I also polish the edges and wipe the whole top with an alcohol wipe to get rid of any stray dirt. And again, only an idiot would do this to a drive they really needed, but its perfect for all those useless 1 and 2 gig drives.
"A coward dies a thousand deaths, the brave but one."
Read the article before you comment. The drives are mounted so that they are VERY clearly visible through the window mod. Not something I'd do, but pretty cool looking.
Yes, modding your hard drive will introduce impurities into it. Yes, you will void the warranty, yes, you will offend the Gods and generate additional RF.
But, it's a mod that you do because you want to, damn the consequences. It's done....for fun, for the hell of it, because you can, because it's there.
Chill out, lay off the "Yeah buts" and applaud the chutzpah that it takes to actually do this....but do not try it with ANYTHING mission critical!
Well given what you said I don't think you did EMC testing for the FCC and UL. Your description of how a _Faraday_ cage works is stunningly wrong.
A good conductor reflects incident waves very very efficiently. Very little power is absorbed by the metal itself. If you surround a region with metal, all incident radiation from outside the box is scattered and does not enter the box.
If you want add a transparent window to the box, all you have to do is integrate a metal wire mesh fine enough so that the gaps are much smaller than the wavelengths of the frequencies you want to filter out. So, to filter out all frequencies below 2.4 GHz (lambda = 12.5 cm), you want a mesh much finer spacing on the order of 1.25mm - 1.25cm. (How do you think your microwave oven window works?)
Only if you are talking very low frequencies, would even talking about "goes to ground and out" have any meaningful content (like 60Hz which is essentially the same as DC from any electromagnetics theory standpoing unless your devices are the size of the continential U.S.)
Kevin
P.S. By the way, my Ph.D. background is electromagnetics and I had an office inside a Faraday cage at a former employer.
They don't.
The FCC doesn't approve specific components. The FCC's approval comes from demonstrating that the entire finished unit's emissions are below a set of thresholds.
Notice that you will see FCC notices on manufactured parts (i.e. a large companies store bought PC, a monitor, a laptop, etc) but not home brew machines. This is because the manufactured computer was tested for emissions and found to comply; the home brewed part wasn't.
Technically, you arn't supposed to operate non-tested devices. Even if a device is tested there are two seperate "levels" of complience, A and B. FCC A okay's the device for use in (a presumably noisy) industial setting. FCC B okay's the device for residential and home use (lower thresholds).
And in case you were wondering, yes, it is illegal to operate a machine that exceeds the FCC's emission levels because the machine could interfere w/ legitimate uses and approved devices (i.e. air traffic controlers). Considering some slashdoters don't have the expensive test gear it is probally a bad idea to start opening holes in otherwise well thought out cases.
Coming from someone who has done this in a professional environment (opened drives), I would say you are lucky, or did this to a relatively old drive. I have seen the effects that small amounts of dust can have on a drive.
Older drives have had fly heights higher than a particle size, meaning little effect from the presence of trace amounts of dust.
Current drives (last 4 years or so) have VERY low fly heights. They are designed to maintain an altitude over the drive platter that is generally smaller than a visible dust particle. A dust particle that becomes lodged like this on the disk head will draw cyclical patterns of dead/error sectors on the disk (yes, I have seen this, many times). In many cases, you will not have catastrophic drive failure, but you *will* have damaged sectors.
Even if the platter is "tough" enough to take this, the contamination is likely to accelerate corrosion (something that a disk head has no tolerance for), you risk damaging the head from particle impacts (at 7200+ RPM, that particle sticking to the drive surface can do some considerable damage).
Dust contamination may take weeks or months to develop problems (there is a small whirlwind going on in your HD, it is just a matter of time if there is any free dust in there). Taking a drive apart, then putting it back together, and watching it spin up would be an extremely naive method of calling it functional. If you are lucky, you didn't drop too much dust in there, and the filters in the HD would pick up most of the particles.
Also, some of the damage is not permanent. Reformatting the drive, or rewriting the sectors will clear the damage (really partial corruption). The heat from the particle being dragged across the surface of the disk may flip a few bits here and there.
Now, TVs, VCRs and power supplies are ALL DESIGNED TO BE OPEN to the air. You wouldn't crack open the TV tube, connect your Hoover to it and plug the hole with Fix-a-Flat, would you? The only part in a VCR that is really a problem to have dirty is the head (which is already exposed daily). That can be remedied with a solvent. You'd be an idiot to use any solvent on a modern HD surface, you'd be sure to crash the head then (film residue, most platters are coated).
As for the conspiracy theory regarding data recovery: it is your risk to take. If you can't afford the recovery fee, find as clean of a place as you can find to open the drive, and DO NOT TOUCH THE PLATTERS WITH YOUR FINGERS. Only touch them at the edges with clean plastic. Read the data off the drive, and consider the "new" drive dead. It will not live forever.
Also, this is only useful if the head dies in your drive. If the platter is scratched, it will destroy the head of the new drive as well (if it works at all).
OK, quick quiz.
What gets written to your swap? Pages from your memory!
Pages get corrupt, swapped back in... instant swiss cheese computer.
I'd say it's a lot more safe to use one of these drives for unimportant storage, than something critical like swap. You are basically adding bad RAM to you system in essence.
I've had enough abrasive sigs. Kittens are cute and fuzzy.
I used to work for a disk drive company that used to design/build enterprise drives (SCSI) and we used to put clear covers on demo models for show. This worked fine until we started using MR heads (GMR used now) as MR heads are extremely sensitive to ESD (electrostatic discharge) and most plastics are insulators and thus they don't dissipate a charge (the best material for ESD is static dissipative materials which fall between an insulator and a conductor).
What happens it that the air rushing inside the case will create a difference in electrostatic potential and when it gets large enough zap, and there goes the head. Please be advised that you won't see this happen as the amount of ESD to fry a MR stripe is extremely (worlds most sensitive fuse) tiny and a human would not even feel it.
If these drives work very long at all I would be very surprised!
Yes, two identical IMB Travelstars. Same size, same model number. One ticked and burped on startup, the other had a password lock on the platter (which the controller knew about, and so wouldn't play ball). They were bought as seen on eBay for next to nothing, so I didn't expect them to work, and really had very little to lose.
Isn't the 75GXP the model that a lot of people had problems with? And the problem was with the physical platters breaking down? I'm not sure what you'd gain by moving the platters to a new drive, unless you know that it's the head, arm or motor that's screwed. In the first instance, you could try the controller from an identical drive. Swapping platters really is the last resort of the desparate, I think. ;-)
If you were blocking sigs, you wouldn't have to read this.