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View Full Version : Hard Disk Bad Sectors - What causes them

BigAL.NZ
10-30-2009, 10:20 PM
I have a interesting one here.

Installed a new hard disk in a guys PC, because he had quite a few bad sectors. He comes back a week later complaining about the computer. I rescan and low and behold quite a few bad sectors again.

So I replace the disk. Now he has brought the computer back a 3rd time - and AGAIN its got bad sectors.

Now as I understand it sudden movement while the disk is spinning, manufacturing faults. But what could be casuing this?

Short of programs like MHDD I didnt think software could make faults (I am thinking of a trojan/virus etc?).

User swears black n blue they have not bumped it.

-Al
PCSupportGlasgow
10-30-2009, 10:26 PM
bad psu.

as you stated you know the reason for the cause of movement and halts so think back what causing and powering it.... oh maybe sudden jolts and drops in electricity.
BigAL.NZ
10-30-2009, 10:42 PM
bad psu.

as you stated you know the reason for the cause of movement and halts so think back what causing and powering it.... oh maybe sudden jolts and drops in electricity.

I had thought of that too, and the PSU in this PC is damn old. But isnt that what TVS diodes on the HDD PCB should do? Sacrifice themselves in the even of any power spikes?

I can stick some scope probes on the molex or even just with a DMM to confirm your theory or not?

-Al
BigAL.NZ
10-30-2009, 10:45 PM
I had thought of that too, and the PSU in this PC is damn old. But isnt that what TVS diodes on the HDD PCB should do? Sacrifice themselves in the even of any power spikes?

I can stick some scope probes on the molex or even just with a DMM to confirm your theory or not?

-Al

4.9v and 12.46v - so both within 5% although the 12v us getting a little on the high side. In any event it could be a spike?

-Al
Daifne
10-30-2009, 10:47 PM
How is he shutting down the system? Does he do it the proper way through the Start menu or is he just holding in the button?

Yes, I know, simple and obvious.
BigAL.NZ
10-30-2009, 10:52 PM
How is he shutting down the system? Does he do it the proper way through the Start menu or is he just holding in the button?

Yes, I know, simple and obvious.

Good question. Will ask.
BigAL.NZ
10-30-2009, 10:55 PM
bad psu.

as you stated you know the reason for the cause of movement and halts so think back what causing and powering it.... oh maybe sudden jolts and drops in electricity.

This is where one of those Fluke 289 DMM's with logging would be nice....leave it wired up to capture data over night.

Next on my shopping list :-)

-Al