Disk Doctor–Advanced Hard Disk Drive Repair

What’s wrong with your hard disk drive?

If it’s not fixable at home, and it’s probably not, i trust Disk Doctor enuf to try them.  See below.  But first, some background material.

An excellent introductory video on hard drives is “Hard Drive Click of Death Explanation and Live Demonstration” on youtube. (If that ever disappears, i have it saved locally.)
There are several possibilities of what’s wrong with your disk.
The main components of a hard drive are a pc board (In this case, “pc” means “printed circuit” as in “printed circuit board” rather than “Personal Computer” which is more common). The pc board (also called “pcb” for short) is the “brains” of the drive. This pc board is also the thing that talks to the rest of the computer.

The drive has platters, magnetic wonders which contain billions of bits information arranged in concentric circles. This platter spins at high speeds. 5400 rpms. 7200 rpms. even 10,000 rpms.

The drive also has a “head” which scans across the spinning platters and reads the bits of information. The head floats on a laminar sheet of air that’s billionths of an inch thick.  Ie, really, really tiny.

NOTE: If you ever hear new noises coming from your drive, BACKUP IMMEDIATELY.  It is going to fail soon.  You dont know who much time you have.

So what could be wrong?

  1. The head that reads the platter might have physically broken.  This is the most common reason.  This results in a repetitive clicking sound.
  2. The motor that spins the platters might have broken.  If you put your head close to the drive, you can hear the platters spin up to speed.  It sounds like a whirring sound which gets higher and higher pitched as the drive spin gains speed.  If you dont hear that, it could be the motor (or the pc board failing to give the motor the right instructions to spin up).
  3. The pc board may have broken in various ways.  There’s a ROM chip on it that contains firmware and initialization data for this particular drive, including the map of bad sectors.
  4. If you hear a clatter in your drive, it’s likely your platters are vibrating. Stop the drive and restart it. Tho sometimes this resolves itself harmlessly without restarting.  But it is time to BACK UP YOUR DATA if you hear this.  Trouble with the motor that spins the platters can also sound similar to clatter.  Also the bearings that ease the friction between the moving parts can wear and sound like grinding, which is also similar to a clatter.

How to fix these things at home.

  1. There are two things you can do that require removing the pc board from the drive.  This one is is the easy one.  CAREFULY unscrew the screws (usually torx) that keep the green pc board fastened to the drive.  If your screw driver slips and you scratch the pc board you’ve probably ruined it.  The pc board is usually on the “bottom”.  CAREFULLY pull off the pc board.  There are several “contacts” small, usually oval, pads of metal that contact other parts of the drive.  The pads can be on the drive side or the pc board side.  Get a new pencil eraser, that’s clean.  Rub it on the contact pads to rub off corrosion.  Reassemble the pc boards.  This helps occasionally.
  2. I have heard negative recommendations about putting your drive in the freezer.  It is said that if the drive has air exchange with the outside, condensation will form on the platter.  A water condensation droplet is ginormous compared to the head “fly height”.  But if the drive is sealed, then you’re safe, and you can take advantage of the different temperatures which can change the way the electronics work, and physically shrink the dimensions of components, and you might get lucky and it might work.  Unfortunately, I dont know how to tell if the drive is sealed.
  3. Other than freezing, you can power up the drive, hold it in your hand, and spin it violently in a plane parallel with the platters. This might un-stick the motor or make the head pass a problematic spot.  DONT DROP THE DRIVE if you attempt this.
  4. The other possibility is to buy an identical drive, and swap the pc boards. And when i say identical i mean really, really identical. The main part number, the sub-part number, all those funny character codes on the drive, front and back. And try to get drives that were made in the same month. So, as i said, really identical. I guess these drive manufacturers are always tweaking things. However, from what i hear (i have not personally confirmed) drives made in the last decade, ie most drives, have a ROM which stores parameters specifically tuned to this physical drive, ie compensating for any physical variances which have appeared on this particular unit. Including the map of bad sectors. So they say if you swap the pc board, you have to move the ROM from the old drive’s pc board to the new pc board. This involves heat to un-solder the two ROMs and heat to solder the old ROM into the new board.
    • (Calling it a ROM chip is a bit misleading, cuz ROM stands for Read-Only Memory, and this memory is written to, because the drive updates it. That means it’s programmable, or PROM.  However, since it’s programmable from the pc board it is likely an EEPROM, or Electrically Erasable Programmable Read-Only Memory chip.  Regardless….)
    • It’s also called a BIOS chip. How can you identify the HDD PCB’s BIOS?  All of the chips with 8 pins (4 pins on each sides) labeled 25P05VP、25P10VP、25F512、25F1024、25F1024AN、SST25VF512、SST25VF010, eg. are BIOS chips. There are not many 8-pin chips on the PCB, so they are easier to find than they could be.  [There may be other types of BIOS chips not listed here.]
    • If there is no 8-pin BIOS chip on the PCB, it is likely the BIOS is integrated on the Main Chip IC, or Controller. (“IC” stands for “Integrated Circuit”.) It is more complex to exchange the Main Chip IC than exchange the BIOS. If you plan to try this, it would be wise to attempt it several times on the PCB of a different HDD, one who’s data you can afford to lose.  Practice makes perfect.  But at this point you might want to hire a(n expensive) company.
    • I can not vouch for the videos below, but it found them interesting as background:
    • Why Control Board Swaps don’t work anymore   by Gillware Data Recovery    http://www.youtube.com/watch?v=ICR-xw1FYlU
    • DIY: Repair Hard Drive PCB. How to swap circuit board ROM chip.  by Donor Drives  http://www.youtube.com/watch?v=Yn2eL4o-6Eo

Disk Doctor    http://www.diskdoctors.com/

I called Disk Doctor

They are expensive.  $450-$850 if it is NOT a mechanical problem.  $850-$1600 if it IS a mechanical problem.

It all hinges on: Do they have to open the drive and work on the motor, head or platters?  If so, they need to use their (expensive) clean room.  That costs big bucks.

If they only need to work on the pc board, then it’s cheaper.  Not cheap, but cheap-er.

They have a free diagnostic service.  Then they will tell you what price range you’re at.

And if you decide not to do it, you CAN get your hard drive back.  Perhaps to consider other options, or perhaps to wait until later when you can afford the fix.

But as far as i can tell from a phone call, they can be trusted.  I talked to a technician, twice.

He explained that the ROM BIOS chip contains the firmware, the map of bad sectors or blocks, and tuning data for the drive.

He explained that the first thing the drive does when it powers up is read a special sector to initialize itself.  That data must match what’s in the ROM.  If not, then the pc board never initializes.  And you can often hear a clicking sound.

The pc board both controls the reading off the platter, and also talks to the computer. It must be healthy and speaking the right language for the PC to recognize the drive.  But does the pc board need that first disk read before it can talk to the PC.  Yes, the tech assured me.

The tech confirmed that most of the time the problem is with the head.  That means opening the drive, using the clean room, and $$$$ 🙁

And he explained to me that they can measure various currents at the drive interface (without opening the drive, ie without incurring the clean room cost) and tell what is wrong with the drive.

I trust them enuf to give them a try.  If they can successfully restore a couple drives for me, i would trust them fully, but i havent gathered that data yet.

Leave a Reply

Your email address will not be published. Required fields are marked *