Replacing HD platters

[st3]

I figured this was the best place to put it, but if you want to move it, by all means.

I have an HDD that had a major mechanical failure a few months back. I don't really have the money for data recovery (drive savers quoted be 1900-2900) So I figured I might try and swap out the platters. I know that they say that if you crack the seal out of a clean room the drive is basically FUBAR because of dust and whatnot, although I figure besides the cost of the replacement drive (less than $100) what do I have to lose?

Has anyone done this before? When/if I get it open can I replace the platters with common tools? I have a set of electronic bits that are all small (torx, hex, pozi, phillips etc) but I don't know if say some of the stuff is riveted in place?

-Pete

 

[sao123]

Youll need mostly jewlry size torques screwdrivers...
But its nearly impossible to replace the platter without damagin the read/write head.

 

[FrankSchwab]

Having taken apart my share of old drives (the magnets are quite useful), I'll say that you have nothing to lose.

Nothing to gain, of course.

Normally the drives are held together with small Torx screws. There will be a half-dozen on the top of the case, and one or two under stickers on top of the case. Remove them all and pop the top. Closely examine the inner workings - quite simple, but fiendishly complex.
To remove the platters, you'll first have to get the head assembly off the disk and out of the way. I don't know how to do that without horribly mangling the alignment of the arms. You might be able to unscrew the magnet assembly (from the bottom side of the drive; you may have to remove the controller board) and remove it, then unscrew the pivot for the arm assembly and remove it.
Next, remove the screws around the hub. Should be 3-6 of these. You can then unstack the platters - noting the precise alignment of the platters, because there is no keying to allow you to put them back aligned.. Find the munged platter(s).
Find a precise duplicate of the drive. Dissassemble it the same way, and replace the munged platters with good ones from the new drive. Note that you'll have absolutely no way of knowing how to align the replacement platters with the existing platters. Guess, and hope that you get it right. There's at least one correct alignment out of several million possible.
Re-assemble the drive. Plug it in. Let us know how it turned out for you.

/frank

 

[CTho9305]

Will the heads get damaged when you bump them around while moving the platters?

 

[Codewiz]

You need a drive that is exactly the same if you want to read it. Take the case apart. Remove the circuit board on the back. Remove the heads. Remove the platter.

I have done it before trying to recover a women's thesis paper in college. We even used a clean room(cool experience). We were however unsuccessful.

 

[bwnv]

Removing the platters will get you nothing, unless the drive only has one disk. Any more than that and you mis-align the servo tracks on the platters. Data recovery places mostly read the data bit by bit, but the machine to do so is anywhere from 60k to 300k.
Your best bet would be to buy an IDENTICAL drive and try swapping the board uot. Good luck

 

[FrankSchwab]

Originally posted by: CTho9305
Will the heads get damaged when you bump them around while moving the platters?

Not being a disk drive engineer, I can't say authoritatively.

However, in the vein of my previous answer, I'll say:
When you remove the head assembly, be very careful to keep the heads from banging into each other or anything else.
When you replace the head assembly, be very careful to keep the heads from banging into each other or anything else, and be sure to let them land back on the disk very gently.

Personally, I think neither of these warnings can be met by the average home tinkerer. I'm pretty sure Maxtor, Seagate, WD, et al, has technicians who are capable of it, given the appropriate tools and fixtures. I'm not at all sure that even they can replace a platter and retrieve anything off the drive.

/frank

 

[Mark R]

I took a drive apart once, and after I bumped the heads on the platters it was never the same again.

Previously it sort of worked, sometimes. Afterwards it didn't work, at all, ever.

Then again, the platters were spinning when the collision occurred.

As far as taking the platters out, I really struggled getting the platters off the spindle - in fact, I couldn't do it without wrecking them completely.

 

[bwnv]

Also, if it was a head crash (high pitched screatching noise while spinning) than the heads and disks are already toast so take it apart for fun. Another trick if the motor isnt spinning up - 1. Peel the sticker off the side of the drive where the platters are.
2. place a small screwdriver against the edge of a platter. 3. press the power button while flicking the screwdriver so that the platter spins a little. If the motor doesn't start it's probably the electronics that are bad.

I used to work at a place that did seagate, maxtor and ibm's refurbs, also senior maint. for the first million iomega jazz drives before they moved production to malasia. Although technically they probably could retrieve data they never did due to cost. When they need to replace something inside the drive it gets torn down and cleaned.
Think dirt + servowriter = downtime + lost money
Hope that helps

 

[johnpombrio]

Jeez, I am old enough to have worked on the first hard drives. They were the size of a dishwasher, cost $30,000, and held 10 Megabytes, 5 in a removable platter and 5 on the lower fixed platter (HP 7906). I used to align the heads and replace platters (6 hour job at $190/hr).
The big issue are the servo tracks that are written on the platters. One master track aligns all of the other tracks. Since minute changes in the head position would cause data loss, the servo information is written after the drive is assembled (the low level formatting that you sometimes read about). There are machines that can read a platter information without servo but it is expensive, finicky work. The platter is mounted on a spindle, leveled, then spun up. The head is mechanically worked up and down and back and forth until the signal is strongest. That is done for each track and only then can data be read.
Since the head alignments will be different on each disk drive, I cannot even hope that anything can be read with disc replacement. As for cracking the drive, there are many modders that replace the disc drive covers. Just keep your fingerprints off of the moving parts!

 

[st3]

Well, I wasn't aware/didn't think about the allignment of the platters. Just to make sure I am on the same page as everyone else: If all the platers aren't align the same (say 1 is off by a few degrees) the data is unreadable, correct?

I guess that pretty much seals the deal then on not bothering. I guess I will have to sit on it more and think about if I really want that data do I want to send it out.

 

[bwnv]

Originally posted by: st3
Well, I wasn't aware/didn't think about the allignment of the platters. Just to make sure I am on the same page as everyone else: If all the platers aren't align the same (say 1 is off by a few degrees) the data is unreadable, correct?

Atually a few microns would probably render it fubar

I guess that pretty much seals the deal then on not bothering. I guess I will have to sit on it more and think about if I really want that data do I want to send it out.

Like I posted above, did it crash? Does it spin up? If it wasn't a crash I gave you 2 options to try to get your data relatively cheap. If it was a crash it's gone anyway.

Johnponbrio - What you're talking about is dedicated servo, 1 platter just for clock and the servo pattern itself. Last drives I saw that on were the full height maxtors and seagates. Nowadays considering the thickness of 3.5 and 2.5 drives everyone uses embedded servo - all surfaces have servo data. Actually, when I left the field, they were trying to figure out how to write servo using the drives own heads. Maybe they did and that partly helped bring down the priices? Guess we'll see if anyone who's still in the industry chimes in.

B

 

[RichUK]

ive taken one apart for information purposes before... and ill tell you what the magnets that move the read write arms are GOD damn powerfull, i stuck one next to a monitor (CRT) at college and then screen obviously messed up .. but didn't correct itself like it would with a lower strengh magnet .. also i dont know if you guys know that the arms dont actually touch the platters .. just thought i would say that, although you probably know that ... anyways good luck to the OP .. sounds like an adventure ..

Remeber the magnets are REALLY powerfull

 

[Concillian]

As an engineer for one of the companies mentioned in this thread, I can say a few things that haven't been said already, and re-iterate some of the important things as well.

- Be VERY careful of static electricity. VERY. If you don't use a wristband your heads are toast. If you do use a wristband your heads still may end up toast. Heads are about the most static sensitive devices I know of.

- Without a clean room, the best you can do is a humid environment. Use your bathroom with the hot water running in the shower. Leave it steamy for a good 5 minutes before starting so the water can form around dust particles and stick to the various surfaces. The humidity also helps greatly with static.

- Wear safety glasses. you'd be surprised at the particle generation that blinking causes. I can always amaze technicians who think they don't need to wear safety glasses by holding the particle counter near what they think makes the most particles in the room (invariably they pick some equipment that is moving around a lot). Then I hold it up to their face and have them blink once, creating 10x more particles in one blink than 5 minutes next to a piece of cleanroom equipment. face mask and hair net don't hurt either. Something like 20% of all household dust is made up of dead skin. This stuff comes off all the time without you realizing it.

- most consumer type latex and nitrile gloves contain a powder to help glove seperation. This stuff is horrible where praticulation counts. wash the gloves after you put them on before dealing with the drive. You were planning on wearing gloves, right?

- look for any marks on the media under the clamp, and note their orientation. These are likely marks having to do with the orientation of the servo pattern. Older drives had the servo pattern done by the drives in the heads, while many newer drives use an external servo writing method, then the platters are assembled into the drive later. If there is an external servo writing method, there will likely be a mark near the ID. There may only be a mark on one side.

- I reiterate the same drive media replacement. Media may all look the same physically, but media is specifically tailored for each drive. There is a lot of tweaking of both the head and the media because they are dependent upon each other's design. The best media design ever is only that way because of the head it's with. Put it with a different head and it will perform differently, potentially MUCH differently. Also the servo track patterns are vital. If your servo track pattern doesn't match what the firmware expects, you're pretty much out of luck.

- Be even more careful about static then you were thinking about when I mentioned it on the first bullet.

 

[imported_booradley]

You can't do it. No way.

 

[cecallred]

Now THIS was an interesting thread.... one last thing that I've done... and I have several going back to a mamouth 25 Mb drive.... Open it until you have the platters exposed.... Polish the platters ... use them for bookends

 

[CrispyFried]

I have a Seagate ST-225 that I use as an ashtray. Works great and even after submerging it for washing like a thousand times, the bearing are still perfect.

 

[robothouse77]

once dust gets in there, it will create a snowball effect. the particles will bounce around, chipping off pieces of the media, which in turn the pieces of media create more pieces that bounce around and so on and so forth. you have nothing to lose, but don't expect it to work for long.