"Ben Galvin" bravely wrote to "All" (14 Aug 05 11:13:24)
--- on the heady topic of "hard drive repair"

BG Subject: hard drive repair
BG Xref: core-easynews sci.electronics.repair:339614


BG I'm trying to repair my crashed 200Gb Western Digital hard disk
BG (WD2000JB). A few days ago it started making a strange buzzing noise,
BG then about 10 minutes later died completely.

Perhaps the bearing seized or the motor driver IC fried.


BG Ok, so I figured I may as well have a go myself - nothing to lose. I
BG setup up a 'clean room' in my bathroom (cleaned it out, used an ion
BG generator and the hot steam from the shower to temporarily settle the
BG dust down). I know its nothing compared to a professional one, but
BG it's the best I can do. I opened the hard drive for about 30 seconds,
BG enough to determine that the platters couldn't be moved around by
BG hand. I opened another similar hard drive (with no data on it) and was
BG able to move the platters easily, so I'm assuming there must be
BG something wrong with the bearings in the hard disk.

Drives often have a locking mechanism to keep the platters from
spinning when the heads are parked, so not being able to move it by
hand may be normal and doesn't necessarily mean the bearing is seized.


BG I've managed to
BG get hold of another (almost) identical motor/bearing assembly, and I'm
BG going to have a go at swapping them over.
BG My problem is that my hard drive has 2 platters inside it (basically
BG like 2 CDs stacked on top of each other with a 1cm gap between them),
BG but I don't know if I need to ensure that they stay perfectly aligned
BG when I moved them to the new spindle or not (imagine rotating the top
BG cd around a vertical axis by 10 degrees - the data would no longer be
BG sychronised between the 2 platters). There are no marks or holes to
BG tell the orientation of the platters, so it would be very hard to take
BG them both off one spindle, and put them on to the new one and preserve
BG this relationship exactly.
BG Does anyone know if I need to do this, or have any other advise?

One of the platters has clock pulses written it at the factory which
allows the servos to detect the position. Unfortunately the other
platter is mechanically attached so it would be remotely next to
impossible to realign the positions of the 2 platters correctly again.
One would need to align them radially with pico-degree precision or
about 1,000,000,000,000 times smaller than the width of a hair. As one
might guess swapping 2 platters is not a kitchen table top experiment.
Even a data recovery service wouldn't attempt what you propose!

Cough up the big bucks for the recovery service or kiss your data
goodbye.

A*s*i*m*o*v

.... Well I defragged my TV and went all the way back to basic cable!