What's causing these HD's to fail?

[usil]

This is a computer I sold about a year ago. It's been working fine up until about a month ago when it wouldn't load up to Windows. Turns out the HD had many bad sectors. I managed to fix some of them, backed up the data, exchanged the hard disk and reinstalled everything on a new hard disk. Customer goes home happy.
A few days later, they come back saying the computer doesn't load up again. I check it and it has some bad sectors again. I managed to fix all the bad sectors, ghost the HD and decide to give them a new hard disk. I put the ghost on the new HD and send them on their merry way.
2 days later they are back here, same problem. I am checking it right now, and it has bad sectors once again.

So 3 hard disks, one a year old and 2 brand new ones get bad sectors within days of being used. They are WD SATA drives. I can't believe this is pure coincidence. Something must be causing this, but what? They have a UPS, which should protect it. I'd think that if the UPS was faulty and was zapping the computer with some high voltage, the motherboard would be the first thing to go.
So any suggestions to what can cause this?

[Steve R Jones]

When you say you reinstalled everything - is that from scratch or are you using Ghost and the image might have some sort of issue?

[Steve R Jones]

Oh and were the two new drive purchased at the same time?

[Train]

Some one is not using the windows shutdown and is just turning the power off.

Whether the switch on the PS or jerking the plug from the wall or a button in between it makes no difference.

Anyway what I have run into.

EDIT: SRJ has brought out some valid idea too.

[usil]

Steve, the first and second HD were installed from scratch. The third was ghosted.
They weren't bought at the same time, but the second and third had about a week in between.

Train, they have assured me that they shutdown properly.

Can a bad power supply cause this? I've never seen it happen before.

[Train]

I have a idea they are getting a lot of electrical spikes.

I run into a mess when two 250,000 V transmission lines slapped together a couple years ago.

May need to get a UPS to protect things.

[Steve R Jones]

Faulty ram can cause data to get corrupted as it being written to the drive...That wouldn't explain the bas sectors. (i don't think)

[SuperSparks]

Could it be in an environment where it is subject to extreme vibration, or frequent knocks? A lot of slight head crashes would do that for sure

[usil]

Train, they are using a UPS. I'm thinking that a faulty UPS might be causing electrical surges or something. I don't know, I'm grabbing here.

Nick, it's a regular home environment. No train tracks around here

[Train]

Time to grab a meter and check things out.

[Shinma]

If the UPS in use is a standard consumer version,
Those thing are not much help if their electrical source is bad
and/or
The electrical line is being shared by heavy appliance(s) such as refridgerator, air conditioner...

Before sending the system back to them again,
I would run a full diagnostic on the HDD and memory module(s) installed.

[usil]

If the UPS in use is a standard consumer version,
Those thing are not much help if their electrical source is bad
and/or
The electrical line is being shared by heavy appliance(s) such as refridgerator, air conditioner...

Why is that? I thought a UPS will provide the electricity while protecting from surges from the electricity source.

Last time I returned the new hard disk, I ran full diagnostics on it before I gave it to them and it cam up clean.
I will test the RAM now.

[Shinma]

Unfortunately, not all UPS designs/technologies are the same.

• Additional reference

Not limited to generics brands,
Encountered issues/failures with APC Back_UPS CS, LS and even Smart-UPS models.

[usil]

I've been selling the same brand and model for years and it's never happened before, despite my area having many electrical problems. Could be that this specific UPS is not working properly. But wouldn't you think that the motherboard would be the first part effected by electrical problems?

[Shinma]

I would say the power supply.
After that, depending on the design of the PSU,
It could knock out anything.
When I lost a mobo due to a UPS,
It did damage the mobo but it was a gradual deterioration.
Not noticeable at first.