Questions about how ESD affects Hard Drives

[RalphSprint]

I haven't been able to find any concrete answers online, so I figure why not ask the professionals.

What exactly is ESD? Why does it cause problems for hard drives? What type of things would cause ESD?

I opened an old 40gb drive the other day, not in a clean room obviously...and was playing with the platters kind of like a DJ scratching a record lol. Don't ask me why I did this, I just thought it would be fun, and I dont care about retrieving anything from this old hard drive anyway.

In opening the hard drive up...did the dust and my fingers rubbing all over the platter give it any kind of ESD damage?

If I sent this to a data recovery lab, would you be able to get all the data back? I dont understand why its a sin to open up the hard drive in a non cleanroom environment. Cant you just take the platters out and clean them?

In other words...is having the dust and finger grime on it destroying the actual magnetic material on the drive?

[HaQue]

Seems like a troll, but i'll bite.

ESD is electro static discharge.
a charge builds up and discharges into electronics of your drive. It is a very random thing, you might play with drives dicarding any safety precautions and you may or may not damage drives.
what you are talking about is plain old contamination/dirtying or physical damage.

when you rub your shoes on nylon carpet and touch metal and go "oh! damn!" thats what ESD is.

If I sent this to a data recovery lab, would you be able to get all the data back?

every drive different, but obvioously you decrease your chances every time you degrade work environment.

I dont understand why its a sin to open up the hard drive in a non cleanroom environment. Cant you just take the platters out and clean them?

platters can be cleaned - but experienced people still need to be extremely careful.

to understand why - the tolerences in a drive are down to the microns, thousandths of a mm. 1 speck of dust 1/10th the diameter of a human haircaught between the head and the platter can cause a cascading efect of damage. think of a stone under a shopping trolley wheel.

I dont accept this info is hard to find, as in this forum it is discussed many times.

[rogfanther]

In opening the hard drive up...did the dust and my fingers rubbing all over the platter give it any kind of ESD damage?

If I sent this to a data recovery lab, would you be able to get all the data back? I dont understand why its a sin to open up the hard drive in a non cleanroom environment. Cant you just take the platters out and clean them?

1. No

2. Experienced people , who have the right equipment, could take the platters out and clean them. But you wouldn´t be able to pay for this kind of service.

[RalphSprint]

Seems like a troll, but i'll bite.

ESD is electro static discharge.
a charge builds up and discharges into electronics of your drive. It is a very random thing, you might play with drives dicarding any safety precautions and you may or may not damage drives.
what you are talking about is plain old contamination/dirtying or physical damage.

when you rub your shoes on nylon carpet and touch metal and go "oh! damn!" thats what ESD is.

If I sent this to a data recovery lab, would you be able to get all the data back?

every drive different, but obvioously you decrease your chances every time you degrade work environment.

I dont understand why its a sin to open up the hard drive in a non cleanroom environment. Cant you just take the platters out and clean them?

platters can be cleaned - but experienced people still need to be extremely careful.

to understand why - the tolerences in a drive are down to the microns, thousandths of a mm. 1 speck of dust 1/10th the diameter of a human haircaught between the head and the platter can cause a cascading efect of damage. think of a stone under a shopping trolley wheel.

I dont accept this info is hard to find, as in this forum it is discussed many times.

Oh okay, I was under the impression that touching the platter or letting the dust hit it would make it permanently unrecoverable.

[fzabkar]

I remember when HDDs had an antistatic brush on the end of a brass leaf spring. This brush bore against the shaft or base of the spindle and was intended to bleed the ESD off the platters. Such ESD is generated by the airflow. I wonder how modern drives deal with this problem?

[rogfanther]

Since the platters, the axis of the motor and the hard drive case are all metal , conductive and connected, wouldn´t any ESD be conducted to the computer case and from there to earth ?

[fzabkar]

ISTM that, unlike a ball bearing, the shaft of a Fluid Dynamic Bearing would not have electrical contact with the housing, at least not when the motor is spinning.

http://www.nidec.com/en-Global/technology/capability/fdb/

[rogfanther]

depending on the conductivity of the fluid material used ?

As for those brushes in those old 10MB drives, ( I think we had a 80MB 5 1/4 SCSI one that had it ) , were them really necessary, or was it just precautions in a time of better engineering ?

[fzabkar]

In those days the read/write heads were inductive, so they would not have been damaged by ESD, unlike MR and GMR heads.

[fzabkar]

This Nidec patent provides useful information:
http://patentimages.storage.googleapis.com/pdfs/US20090279816.pdf

Ionic liquids are used as lubricants. It appears that static discharges within a regular bearing can cause pitting of the shaft and bearing, so that would explain the need for a brush in the older designs.

[rogfanther]

Makes sense.