Is the motherboard failing or the hard drive?

[PsychBiller]

I have a beloved T40 2373-72U that succumbed to the infamous GPU problem. I was able to buy a repaired replacement board from a very reputable source in this forum. My understanding is that the board came from an R51 1829-5GC. That solved my graphics problem.

It seems that ever since I replaced the motherboard, the hard drive periodically forgets that it has a master boot record. The symptom is a blue screen upon restarting XP that says STOP 0x0000007B. This is generally considered to be an inaccessible boot device. The cause is typically a missing driver (there are no drivers for this), a virus, or a hardware failure.

If I install a new MBR, then I'm good to go for a few hours, a day, maybe a couple of days (it varies).

The hard drive is the same one I was using before the mobo swap: a Samsung HM160HC. The drive has never given me any problems in the past. I've run the Samsung diagnostics for hours and hours with not a single error. There are no errors in the S.M.A.R.T. diagnostics. The drive is not overheating.

I've scanned the system with multiple antivirus and antimalware tools, looking for anything, including rootkits. Clean.

I've wiped the drive with DBAN more than once, reformatted, and reinstalled XP several times. The problem remains.

I can't be 100% sure that the stop error never happened before the mobo was replaced. Is there any way to determine if the built-in IDE controller is flaking out and corrupting the MBR? Any other ideas on how to isolate this to the mobo or the drive?

Thanks. I've lost a lot of sleep on this one.

[RealBlackStuff]

Have you installed the Chipset drivers? http://support.lenovo.com/en_US/downloa ... D=DS001239
(BTW, they are the same for T40 and R51)

[PsychBiller]

Yes, I have installed the chipset drivers. That and the Ethernet driver are the first ones I install when doing a fresh installation.