75GXP Autopsy

[Groltz]

At Overclockers Australia (http://www.overclockers.com.au/techstuff/a_hdd_anatomy/)

[NRG = mc²]

yep... if only more people would open their drives, one just might find a pattern... perhaps (very random speculation) the actuator arm is flexible and distorts at times doing this (if this is indeed the usual reason of failure of 75GXPs).

But then again, doesnt IBM open their drives to see whats going on? Can't be that hard to fix (or to have fixed, in the 60GXP) if thats the problem.

[Buck]

hmmm...

He has a 20 GB drive with two platters for a 75GXP family. So, only three heads are being used. The platter with the scratch was done while the product was open by IBM or Manaz. If you take a drive with the head stack unparked, you can't shake the drive hard enough to get them to move. Even when you move the head stack with your fingers, the heads don't leave a noticeable mark. When you throw a drive and let it hit the ground, it still won't scratch the platters in that manner; usually just divots are created (I’ve sent plenty of drives through the ringer). Since Manaz insists that it wasn't him, I'm expecting the scratch is the fault of IBM. This would explain why a two platter, 4 head (from what I could see there are four heads, although the pictures aren't the clearest) drive is formatted to 20 GB. The scratch mistakenly passed quality inspection and once the drive was closed, they had a problem with that platter side, so they turned the head off. (It is much cheaper to turn off that head once the drive is closed then sending it back through the assembly line.)

This scratch, however, does not directly present itself as the culprit to the drive failing. It does tell us about some quality issues that IBM had during assembly, which could be the cause of IBM’s mass failure.

[time]

Well reasoned, although I wondered if the scratch was deliberate for some obscure reason. It almost looks that way to me. To clearly identify the unused surface perhaps, or to stop it ever being used because it wasn't up to snuff? Pure speculation on my part.

Another good promo for the Nikon 995 though, being able to swivel it to shoot down like that without having a rubber neck. :cyclop:

[Buck]

Good thought Time. If that side of the platter was determined to be unusable before the drive was closed, then the head would not have been installed, or it would have been removed (heads being one of the costliest individual components in the drive).

[Tea]

Damn it! I just lost a post. Luckily it was a picture post, so easy to reconstruct.

Is there a head on that surface?

http://www.redhill.net.au/sf/75gxphead.jpg

Hard to tell for sure from those pictures, but there certainly appear to be blank, naked arms. Compare with this Fireball CX:

http://www.redhill.net.au/jpg/hdd-fireball-cx.jpg

The topmost head on the GXP is well below the top arm. But is it above or below the platter? Above, I think. Need a shot from another angle.

(Tea presses CONTROL-INSERT, just to be safe.)

[time]

Can't be certain, but it looks blank to me.

http://www.overclockers.com.au/pic.php?pic=techstuff/a_hdd_anatomy/actuator_arm.jpg

[time]

:x Oh, very cute, how are they doing that? You'll have to click on this link I've edited:

http://www.overclockers.com.au/pic.php?pic=techstuff/a_hdd_anatomy/actuator_arm.jpg

If that doesn't work, pressing Enter when you've got the URL into your browser may do it. Sheesh!

[Buck]

If Tannin had taken the pictures with his new camera, things would be much clearer.

[Buck]

If Tannin had taken the pictures, with his new camera of course, things would be much clearer.

[Buck]

Stupid delay made be me post twice!!! arghhhh :evil:

And still NO edit button!