Since the SZ1/XP Sony laptop returned from its repair by Sony in France late 2006 we immediately noticed that video held on the hard drive plays back jerkily (both visual and sound),Windows XP boots up more slowly, and we can hear much more hard drive parking clicking noises (coinciding with the orange HDactive light) when running. It's as though the HD reading arm is having to return to rest every 3 or 4 seconds before resuming reading. I have run the hard drive testing utility HDDscan v 2.8 which clearly shows over a 17 minute trace that there were 273 instances of a block reading taking greater than 500ms and 398 instances in the 17 minute test between 100ms and 150ms when all block read times should be approx 5ms or 10ms. As Sony fitted a new motherboard and retained the original hard drive I suspect either the new motherboard or perhaps a faulty cable or could it be a software problem? Could it be a virus? I wonder whether restoring the laptop to its factory state might cure the problem- I would hate to return it under warranty only to find Sony conclude it is not their fault and charge me 100UKP for looking at it!!

Sounds like a dodgy HDD to me.

Either surface degradation or flakey head.

If you run the test again, do the slow blocks appear in the same place?

Ran test again- the most obvious thing is the scrolling stops for about 1 second every 3 or 4 seconds and the red (slow) read then shows as scrolling recommences. Position across scroll width sometimes seems roughly in same column but I'v seen it in at least 4 different columns. This time there were no green blocks. Seems as though the problem remains centred on why the heads are parking so often. Any ideas?

The idea that immediately comes to my mind is: Backup your data! Soon.

Yep- planning to do this today. On thinking about the problem, the analogy that comes to mind is that of a parent complaining about their youngster seeming to take a long time to eat their meal when they have told the poor sprog to run to the bottom of the garden and back after each mouthful! The ability to chew and swallow is not the problem nor I suspect is the problem with damaged read heads or surface. What causes the head to park every 2 seconds? Is it software or hardware? Thus might the problem be solved by putting the laptop back to its factory state using the recovery backup in the hidden partition?

Putting the HD back into a factory state is not going to resolve your problem. I also don't think that it's a virus.

1)before you do anything else, backup your data.
2)remove the drive from the laptop.
3)check the pins to make sure none are bent or broken
4)try a different IDE cable
5)try it on a different computer, u can use a 2.5" to 3"5 adapter cable.
6)Perform a Low Level Format with MHDD or other LLF tool.
7)Send in the hard drive to the manufacturer for RMA.

NOTE: don't send the Hard drive to SONY, but directly to the Manufacturer of the Hard Drive, Western Digital, Toshiba, Hitachi, etc...

I hope this helps

thanks for advice but the laptop is under warranty and I'm certain that if I open it up I will invalidate the warranty. What I need to be sure of is that the problem is not of my making and will be accepted by Sony under warranty. What might cause the heads to stop reading when they should be reading eg a video on the HD? Could it be software or must it be the M/b or a faulty HD?

Well, you mentioned that the hard drive makes some clicking sound. In this case you should be fine, by just sending the laptop back to sony.
If it doesn't and the only problem you have is that video is slow, it could be allot of different things such as: Virus, spyware, slowing down your processor. Bad HD, Bad Video card on your Motherboard, Bad driver. Corrupted software, etc..

Again, if the drive is still making strange noise send the laptop in to sony.
If not you can always re-format your hard driver, & see if it was a software problem.