Intermittent BAD_POOL_ERROR on USB disk access: SouthBridge?

[TKuser]

My T41 has been struggling with a new issue. I haven't added any hardware and can't think of any new software. It's running Windows XP SP2. Connected to a Mini Dock.

I have an intermittent issue that I think I've narrowed down to happening only when I write (or read?) to one of my USB-connected hard drives. I'll probably get a delayed write failure (with perhaps data corruption), followed shortly by a blue screen crash BAD_POOL_ERROR, stop x19. It's happened with various drives, which are completely different enclosures/different brands. It only happens sometimes, although I feel as though it's happening more often lately.

I also sometimes notice when I'm starting the machine that my USB-connected keyboard will have its lights flash a lot more than I'd expect (and, if a drive is connected at the time, the drive will sound like it's repeatedly starting). I've never noticed this keyboard symptom once the machine has been running, nor have had any trouble with the keyboard going unresponsive.

So far, it's only happened with external drives that are mounted via Truecrypt, so I've suspected Truecrypt, but I am lately leaning away from that theory, because a) the keyboard light flashing, and b) my built-in system disk uses Truecrypt and I haven't had any failures there. I originally suspected Truecrypt because what would start to happen was that I'd mount a volume on an external drive, and the volume would immediately dismount itself. I have advanced my theory to thinking that Truecrypt is dismounting because of some intermittent USB interruption.

These symptoms/failures happen whether the device(s) are connected to the built-in USB ports or the Mini Dock's USB ports. I haven't tried disconnecting the Mini Dock from the computer and seeing if the failure recurs.

Memory and disk tests (run from within Windows, not from a boot disc) find no errors.

Does my theory that there is a USB issue make sense? What's puzzling is that it'll happen on the Mini Dock or the laptop ports. Are they driven by the same hardware within the laptop? Could there be a software issue with the USB drivers? I also might expect more keyboard symptoms, but maybe the problem is so brief when it happens that it only impacts a sensitive operation like disk access, and is virtually undetectable to my human-speed finger I/O.

Someone suggested it could be a SouthBridge failure, which I understand can be intermittent, sometimes due to case flex. Does this still make sense, considering I'm using the USB ports on the Mini Dock? And would/should there be other conclusive signs, or might I have some other issue (memory problem undetected by test, Windows driver issue)?

I should add that I am NOT seeing the USB 1.1 speed drop issue, nor are the USB ports appearing to disappear. I'm just having this intermittent blue screen/corruption issue.

I've kept this machine going for over 6 years. I'll be sad to have to build a reasonable Windows environment up all over again.

Thanks a lot for any suggestions!

[poshgeordie]

I've not come across this error but a quick search indicates this

The BAD_POOL_HEADER bug check has a value of 0x00000019. This indicates that a pool header is corrupt.
Important Information If You Have Received a STOP Code

If you have received a blue screen error, or stop code, the computer has shut down abruptly to protect itself from data loss. A hardware device, its driver, or related software might have caused this error.

BSOD's usually indicate hardware issues but some investigation into Pool header issues could indicate a software issue too.

OK, got the science out of the way and onto the practical bit

Are you getting your power for the external Hard Drive via the Thinkpad USB ports rather than powering the HDD from a separate DC supply? If you are there's a good chance you're overloading the USB port and this could be causing the Thinkpad to then shut down (ie Hardware problem).
There are resettable fuses in the USB circuit and it could be that one has gone open circuit to protect the port(s) and this is causes the BSOD.
If you're using the double USB lead that comes with some external HDD's to spread the supply load between two ports, I'd say even this may not be enough to prevent overload on these machines.

Regarding software related issues (as in the 2nd link) I can't help here.

I'm not convinced it's an unsoldered Southbridge chip but some other issue as above.

[TKuser]

A hardware device, its driver, or related software might have caused this error.

Yup, as their page tells us, it's just hardware or software, that about narrows it down. I've read up plenty on the error, and pretty much turned up a seemingly endless list of possibilities.

I do think it would be worthwhile reinstalling USB-related drivers - I suppose to do that, I have to remove the devices, and then hope Windows rediscovers them so I can install them again?

Are you getting your power for the external Hard Drive via the Thinkpad USB ports rather than powering the HDD from a separate DC supply? If you are there's a good chance you're overloading the USB port and this could be causing the Thinkpad to then shut down (ie Hardware problem).

Well, usually this has happened with my small drive that is powered by the USB port. But one time it happened with a drive that's powered by an AC adapter. And, I've been using these drives with this computer for years, and this issue only began recently. And, as I've mentioned, it also happens when the drive is plugged into the Mini Dock's USB, which still has me puzzled. (I guess that scores one for software?)

There are resettable fuses in the USB circuit and it could be that one has gone open circuit to protect the port(s) and this is causes the BSOD.

In that case, I wonder why this would be an intermittent failure? For example, I just ran my nightly backup without incident. Fine last night, too. But the night before, delayed write failure followed immediately by bad pool error BSOD.

I'm not convinced it's an unsoldered Southbridge chip but some other issue as above.

Yeah, it would be nice to figure out what my symptoms really suggest.

Thanks for the suggestions...!