harddrive failures, why ?

[Raven]

hi.

im having a conversation with a fellow about harddrives at another forum and what reduces the life of them.

so i wonder does anyone here sitting on technical information why and how harddrives dies during spinup ?

for example a harddrive can work great for years and one day refuse to even spinup.

the guy claims its due to the motor but considering the motor in a harddrive has no moving parts on its own i doubt thats the reason.

Regards

Raven

 

[Phnom_Penh]

Brushes wear out? or maybe the bearings...

 

[Raven]

the motor in harddrives do not use brushes.

the motor is based on atleast 4 coils that pushes a magnet attached to the discs.

the coils are driven by electronics so their is basicly no moving parts on the motor itself.

 

[Raven]

found this little troubleshooting guide.

http://www.fonerbooks.com/ide_hd.htm

 

[JN]

I was always under the impression that it was just due to the constand expanding and retracting of the moving parts inside the hard disk due to heat.

 

[Raven]

heat is one major problem.

had one really old connor harddrive 200mb which stopped working due to the grease moving out from the ballbearings onto the platters.

with some mild violence the harddrive could be used and used it for almost 3 more years.

googled alittle and seems their is a few basic problems.

1.

handling both at the manufacture and on the way to the customer.

2.

electricity, surges and spikes can kill the electronics.

3.

heat, the hotter the harddrive gets the more risc of failing bearings and the higher the risc of a "misread"

4.

plain wear and tear, even if a harddrive has a POH of 100.000 hours it can still fail.

5.

ESD - ElectroStaticDischarge

i have sofar not found any evidence that harddrives fails more during spinup then under normal use, however several problems can show themself more strongly during spinup such as bad bearings.

 

[Phnom_Penh]

the motor in harddrives do not use brushes.

the motor is based on atleast 4 coils that pushes a magnet attached to the discs.

the coils are driven by electronics so their is basicly no moving parts on the motor itself.

Ok, how about hysterisis or back emf (which would lead to heating)?

Or there is something I heard about the fluid viscosity not being right until after the spinup...

 

[Raven]

back emf does lead to heating but shouldnt pose a problem with the neccessary cooling.

http://www.newton.dep.anl.gov/askasci/phy00/phy00351.htm

hysteresis.

http://columbia.thefreedictionary.com/Hysterisis

the fluid in the FDB might be thicker when cold which would cause a higher drag but thats probably something the manufactures have thought about and tested.

possible it can react in a negative way and get thicker but could also get thicker when the harddrive have been used for along time and small metallfragments creating more friction.

also FDB is good but the axel can still hit solid material.

will se if i can find a schematic on a FDB.

will also se if i can get ahold of a manufacture's support department and se what they have to say.

 

[Rastalovich]

I don`t think HDs like temps around 70 degrees. Alot of people tend to cool the major components of their pcs and neglect their drives (me included). Being placed near optical drives doesn`t help as they like to make heat just for the sake of it. Manufacturer-wize, they tend to stick them at the top of the pc which isn`t ~really~ the best place for an optical drive - find me an upside down pc case tho ?!?!

Electrical items inherently have a life expectancy. This given from the manufacturer cannot be based on pcs that are bent from their ideal situations. I can see their white painted, air-con, cleaned daily, test lab. NOT downloading torrents on unfragged volumes, not subject to room climates through the summer and definately not left for years to test - more like extrapulated results. I think if a user gets 5 years or so they`ve done well.

I`d doubt, although they should change their opinion, that manuf`s idea of an average user, surfs the webs for more than an hour or so, uses word for an hour or so, plays minesweeper for an hour or so, then switches off. Demands are a hell of a lot higher than this today.

A pc left off and stored for a "long" (can`t define long) time will have a drive fail. This would be due to the drive head, maybe not properly parked, sitting on the same surface position which results in a footprint being created. Many pcs with a simple windo$e problem, then get shut off and stored til some1 gets around to looking at it, seem to have had failiures - but it`s now showing a different circumstance than the original OS problem. I don`t know whether a Park command still exists in DOS... been more than 10 years since I`ve used it. -- similar can be said about drives taken out of pcs and shelved for months, then found to be dead when next used.