Demonstrating a method for hard disk repair by replacing the read/write head from a Maxtor d540x-4k020h1 (20gb 5400 rpm, single platter) hard disk. Not for the faint of heart.
1) I take absolutely no responsibility for any damage accrued to any piece of hardware while attempting this procedure. It is 100% completely at your own risk. Opening the drive WILL VOID YOUR WARRANTY! The likelihood of success is STILL UNKNOWN since I have yet to receive a new controller. However, if you read on, you may come to realize the feasibility of such a task. If anyone has a Maxtor d540x-4k020h1 and is willing to sell it, please email me – Thank You.
2) Opening a hard disk and exposing it to the air may cause permanent damage to the data stored within.
3) The alignment of the permanent magnets may pose an issue. They need to be aligned exactly right. Take notice of the position of the upper magnets before you unscrew them.
A friend of mine who runs a decent size manufacturing company had kept various pieces of data on this drive. Being only one year old, and part of his Dell computer, he never thought twice to back anything up. Needless to say, the drive crashed without warning. Under close observation, I noticed that the drive didn’t spin when powered up. It seemed that either the controller was damaged, or the spindle motor had possibly burned out. The data wasn’t critical and most of it just needed to be typed back in. The finances weren’t available to send the drive out to a data recovery center, their work often costs between $1500 to $5000 dollars USD. He had decided to forget about it unless a less expensive alternative could be found. I was definitely up to the challenge; especially knowing there was nothing to lose.
I began by inspecting the controller for obvious damage (i.e. burnt parts, etc). At this time, I was unable to see a problem. However, I did remember that the drive did jitter when power was first applied, so I knew there was power on the spindle motor, at least for part of a second. Furthermore, if power was present on the spindle motor, and it jittered momentarily then stopped, then the motor was either stuck or perhaps the applied voltage had dropped. I briefly opened the drive just to ensure the spindle motor wasn’t jammed. It wasn’t. Then I closed the drive and began to troubleshoot an electrical problem. I removed the controller board from the drive and systematically masked off with masking tape the 20 pins or so between the controller and the internals of the hard drive. After trying several pins, I managed to discover a pin which in fact, when covered (and the controller back on the board) allowed the drive to spin up properly. Unfortunately, the drive would not be detected by the BIOS, nor did there appear to be any head control. The drive would spin then slam the head side to side against the head stop inside the drive. This was definitely not good.
It seemed this pin had some vital role in controlling the head movements. After re-opening the drive, I traced the faulty pin to its destination, a small chip on the side of the armature carrying the head.
There was no way I could repair this – UNLESS…
Hard Disk Repair Solution:
Cannibalize parts from another hard drive to get the first one functional.
I purchased an identical drive on eBay. However, I first tried the easy way out. I moved the new controller onto the old drive and powered it up.
BIG MISTAKE. The new controller immediately cooked itself. Now I was definitely sure that the chip mounted on the side of the head armature was directly responsible for dropping the voltage applied to the spindle motor. I imagine this pin shorts the controller which then stops applying voltage to the spindle motor. So I was exactly back where I began except that now I had two burned controllers. I decided to do what had to be done and move the head from the good drive to the old drive. Moving the platters seemed impossible and obtaining the right tools would not be easy.
- Needle Nose Pliers.
- Philips Head Screw Driver.
- Small Flat Head Screw Driver
- T9 Torx Head Screw Driver.
General Tips Before Starting:
- Attempt to work in the cleanest area possible. A garage is usually not a good choice.
- While working within the drive, work slowly and carefully. Be sure not to touch the platters with your fingers or tools! This will most likely damage the data on them.
- The goal is to remove the heads from the good drive and then later transplanting them into the broken drive. Again, we are moving the heads since the bad chip is affixed to the head armature which
directly connects to the actual read/write head. Since there is little chance of removing the chip
successfully, I am attempting to move the entire head/arm mechanism instead.
- First, remove the screws holding the controller board to the back of the drive.
- Pull the controller off.
- Flip the drive over.
- Remove the Philips head screws holding the drive cover in place. There are two T9 screws under the stickers, the hold the top of the spindle head armature bearings in place. Remove them. Remove any additional screws holding down the cover until the cover becomes loose.
- Take the cover off of the drive and set it aside.
- Remove the two screws holding the pin bracket that attaches through the casing to the backside of the controller. Do not try to remove this yet.
- Remove the single screw holding down the top magnet above the head armature.
- VERY CAREFULLY, use a small flathead screwdriver to pry the magnet off of its seat.
“Will this erase the charges on my credit card?”
WARNING! These magnets are very strong. Do not allow them to get any closer to the platters than they are while positioned in their mounting places. THIS WILL DESTROY any data on the platters!
- Set the magnet down away from the drive and prepare your needle nose pliers. . . .
The next step is to remove the head locking mechanism.
- Carefully squeeze this piece of plastic gently, but use a moderate amount of force to lift it off its mounting pin. It takes some effort, but it will come right up. Be careful! Both this plastic device as well as the one in the next step are both very
fragile and can break easily if squeezed too hard!
- Next, remove the head stop mechanism, located as shown in the picture just above. Again, squeeze gently and lift it straight off of the pin.
- Gently slide the head off the platter. It will sit nicely in the air without the platter underneath it. DO NOT touch the heads with your fingers or any other material. This may damage them.
- Now, prevent the head from moving by holding your finger above the bearing on top.
- While doing this, turn the drive over. You will see a
Torx screw just below the head (below the controller you removed). Remove this screw carefully. This is the last screw holding the heads into the drive chassis.
- Lift the head straight out of the chassis. When it is clear, gently pull on the connection block you removed the screws from earlier. It will lift straight out of the chassis with the heads.
- Take a deep breath, you are halfway there.
Now, do the exact same procedure to the drive with the bad heads. Once both sets of heads have been removed, simply put the good set of heads in the old drive chassis. The installation process is very similar to the removal process. When you insert new heads into the old chassis, be sure to screw the bottom of the head armature in while the heads are not over the disk. Then gently lift on the arm carrying each head (in this case there was only one) to slide it back over the disk. At this point, you should test the arm by swinging it back and forth very slowly and carefully. It should not drag on the disk whatsoever. Reinsert the drive stop and headlock, and then the permanent magnet. Re-close the case, and screw the controller back on. Now you should be finished! Plug the drive in and you should be set to go.
This is a last-ditch means to get data out, and you shouldn’t count on this working. If you absolutely, positively MUST get that data out or you’ll lose thousands and thousands of dollars, look at a data recovery center.
If the data isn’t worth THAT much, and you’ve exhausted all lesser options, you might want to try this, but there’s a lot of things that can go wrong, and there’s no guarantee or even probability everything will be OK if you do this.
It’s an interesting project, though.
Having worked for a major hard drive manufacturer repairing damaged/destroyed hard drives for a living, I have one small note about the procedure taken to repair the drive:
The read/write heads are more sensitive than can possibly be imagined. There is a term that should be introduced here: Head Slap.
Sounds like the heads smacking together violently, but it’s much less than that. If the top and bottom heads for a single double-sided platter ever touch, they are damaged to some degree. Now here’s the fun part: You may not actually damage the reading/writing element, as they are the size of a spec of dust in the middle of each head. However, the heads are made of a silicon material, much like IC chips.
The heads have an amazing role in the drive. As the platters spin, the disk surface generates a small “film” of air that spins in the same direction as the platter. As the air passes under the head, the design of each head is such that it forces a very small amount of air under the head and gently lifts the head off the surface of the disk, ever so slightly so that it doesn’t ride on the surface. (BTW, the innermost ring of the disk surface of all platters is called the landing pad.)
In order to keep the heads from flying too high off the disk surface, a small amount of downward tension is built into the armature to provide a spring effect. When you slide the armature across the disk surface, you introduce small, probably microscopic, scratches into the surface of the platter. You also wear away a very small amount of the silicon of the head.
Now when you make it to the edge of the platter, the two heads are no longer separated by the platter and slap together ever so gently. In the microscopic world, the slap is like smacking two skyscrapers together. Maybe they don’t splinter into a million pieces, but infinitesimal chips and cracks appear in the surface of the head. Not necessarily the read/write element, but definitely in the silicon around it.
When you put the device back together, you introduce stress, and over time – maybe a week, maybe a year – the surfaces scratch, wear down and the head doesn’t fly anymore. New term: Head Crash – when the heads simply grind the surface of the platter to dust while committing hara-kiri and turning the inside of the drive case into a black powdery mess.
I’ve seen it – pretty cool – but not good for storing or retrieving data for that matter, as the data is now separated into little particles and splattered all around the inside of the drive case.
(Another BTW: By scraping the magnetic film off the platter and randomly distributing it around the inside of the drive case, you effectively render the disk unreadable, which no amount of money will enable a drive recovery company to bring back. Food for thought if you need to truly delete files from your hard drive.)
So how do you do it without destroying the drive? Build yourself a comb system that will spread the heads apart and lift them off the platter surface before you move them at all. We use a series of metal fingers that are tapered to get under the armature and lift the heads.
Then swing the armature and comb assembly out and remove, but if you take the comb out – Head Slap! If we ever allow heads to touch, they are in the trash can a second later. The point is, you can’t see the damage done and it may not be catastrophic, but it will lead to early drive failure.
Just thought I’d let you know. You could probably put together something to accomplish the head lifting armature swinging maneuver, but be careful. Make sure it securely holds the heads apart while rotating them out from the platters and keeps them apart while you make the switch.
And never let anything touch or slide along the surface of the platter!
I’ve included a very simple quick sketch of the comb I’m talking about:
Also, the whole cleanliness thing is crucial.
Not that you can’t do it at all, just be very sure that no dust or small particles enter the case. Imagine if one of your eyelashes hit the platter surface. If it’s there when you spin up the drive, it might get wedged under a head and accomplish pretty much the same thing as a chipped head. Remember that black powdery mess?
The following (TM Microscopes) link shows what happens to the physical disk when a drive is shocked (not electric, physical) – a different kind of head slap occurs.
In this case, the head lifts off the media and smacks back down with enough force to deform the magnetic layer of the disk. Sometimes you can see them as anywhere from 1 to 4 dots in a rectangular pattern on the surface of the disk. The four images on this web page show a visible image next to the magnetic signature of the same area. Their point in showing this is that the little lines of magnetic force are actually altered by the collision. When you alter those lines, you corrupt data. So even though it may not be major, you can easily lose data by simply dropping an HDD. And it doesn’t take much to do that. When I was working at the manufacturer, we played around with a mock-up of an empty HDD outfitted with accelerometers. Those are the little guys that tell you how much force is being exerted on an object. (Same thing they use in crash test dummies.) We’d play with them and see how high we could drop them without exceeding a given value. (Memory fails me and I can’t remember what it was.) Typically, it only took a drop of 3/4-1 inch onto a hard surface to see damage. Suspension systems are much better now, but still don’t absorb a lot of the shock. And once you dent the surface of a platter, it’s like putting a divot on a putting green. Part of the material is depressed, while the rim raises up above the surface. Spin up the disk and the head will smack it every time it passes over that spot. Eventually, you get a head crash. Another thing to be careful with.