Security chip error with replacement motherboard-T42 to T40

[Jas]

I just wanted to throw out a scenario here and see if anyone knowledgeable can tell me what's going on.

I purchased a used T42 MB from a member of this board. First off, I think he was honest when he advertised that it was pulled from a working t42. I'm not entirely sure, however, whether client security had ever been used with it.

I've put it in my old T40 (2373-19U), making it essentially a T42. The memory I have is only PC2100, but that doesn't seem to be an issue. The other parts are basically stock from the T40, and I don't think are a compatibility problem.

I have been able to boot this machine many times successfully, and it has even run for over 24 (maybe even 48) hours. It has also passed all diagnostics.

However, it almost never succeeds in going into standby or hibernate and it irregularly reverts to either hanging on boot (nothing on screen) or throwing the beep code for the embedded security chip (4 sets of 4 beeps).

Thinking that maybe the security chip was messed up somehow, I successfully flashed the BIOS and then got into the BIOS to reset the security chip, also successfully. Briefly I thought I had solved the problem, but I haven't.

Sometimes I can also remove the BIOS battery and all power, drain the board of charge, and then reboot (after resetting BIOS date and time) successfully. Sometimes this doesn't work, though. Almost always I can let the computer sit for a while and then boot successfully (without draining the MB charge).

All in all, I'm just confused. It seems to me that if the security chip was set and I didn't know an appropriate password, I'd never be able to boot at all. Nothing about the computer's behavior seems regular or predictable, but the 4x4 beep code is the only code I seem to be getting. Could it just be a bad, albeit unused security chip? And is there any reason why the motherboard would have been working perfectly in its original laptop but behaving like this in mine?

If anyone has any insights, please chime in. Thanks.

[Peak2Peak]

If ESD pre-cautions were not taken during removal, storage and installation of the MB (and also components which it is attached to), any component / components exposed to any form of static discharge, may have caused major or minor damage - this could lead to intermittent problems.


Note:
The static discharge a person actually feels can be around 2,000 volts (2kV) and above, which will usually destroy most PC components on an MB. (PC tech's usually term this as FRY)
Also a person can quite happily sustain voltages above 50 volts without even feeling it - this can also destroy or partially damage PC components.

With the fabrication of electronic components ever decreasing - for example CPU's being manufactured to 45nm therefore packing in more transistors, it's much more easier to destroy / damage a few thousand of them in one ESD hit!


One more thought - If the MB was ever subjected to any form of twisting or have been dropped, a track may have lifted or broken causing a component not making contact, which also could lead to intermittent problems.

keep us posted if you managed to sort out the problem.

[richk]

It really sounds like a damaged motherboard.

[Jas]

Thanks for the replies. Unfortunately, you're confirming my basic instinct that, at this point, the board is really damaged. It was sent in a padded envelope from the UK to the US, which worried me a little. I am careful to discharge any static from my body before handling parts and I generally work with my bare feet on a concrete floor (and I usually attach a grounded wire to a wrist strap), plus I don't touch anything but the edge of the PC board, so I don't think static damage was a problem on my end.

Ah, well. It's frustrating because it will work for a little while and then crap out, but I guess it's really toast at this point.

[richk]

I think static discharge is less likely than cracked solder or trace, caused by flex. Static damage is more likely to leave it dead. Flex/cracking causes intermittant contact. If it were mine and I were trying to fix it, I would resolder the security chip, the eeprom that holds the settings and the BIOS chip, then after the expected failure, recycle it.

[Jas]

The "expected failure" part is the let down!

[Robbyrobot]

I think static discharge is less likely than cracked solder or trace, caused by flex.

Or possibly a defective component. I've worked on various computers for the past 20 years or so and never once experienced any problem definitely due to static electricity, although this possibility is always mentioned in connection with defective components. When I first started opening cases and touching components, I was accordingly cautious. Over the years, however, I have become pragmatic and handle computer components - mainboards, CPUs, RAM modules and other elements - gently and carefully, but without any particular precautions.

My conclusion is that although the possibility that static electricity may damage components exists, the probability is often exaggerated and is very low under normal circumstances.