KatsBits Community

General Category => Blog => Topic started by: kat on October 05, 2011, 01:22:15 AM

Title: Faulty hardware, nvlddmkm.sys & the BSoD
Post by: kat on October 05, 2011, 01:22:15 AM


Oh boy, the joys of computer equipment past it's use-by date and the resulting "Blue Screen of Death", nvlddmkm.sys error - or to address the issue fully; "STOP: 0x00000116 (0x8941C008, 0x8FA1A9A0, 0x00000000, 0x000000002)" and "nvlddmkm.sys - Address 8FA1A9Ao base at 8FA0E000, DateStamp 4a9cdd24". Normally the cause is a bad driver, either corrupt during install or as the result of something else (usually installing other 'graphics' based applications - video games, video editors and so on).

It can also be cause by faulty hardware, as I recently found when dusting down the innards of the Xa2528 this error belongs to. Turns out the CPU/GPU heat-sink unit covering both chips is held in place by two types of connections; one a set of receiving nuts embedded into the motherboard, the other a similar set of nuts soldered to plates on the outward facing surface of said-same board. I've no idea why it wouldn't occur to the designers of the laptop, Fujitsu-Siemens in this instance, that doing that was possibly the worst way to secure a component that is under a constant and tremendous amount of tension, as CPU heat-sinks are - the joint is only ever as secure as the strength of the solder holding the mounting nut, and these modern 'lead-less' solders have a tendency to become relatively brittle over time causing connections to break.

The result? An improperly cooled CPU or GPU resulting in overheating or various other sundry problems that may, or may not, manifest as the "Blue Screen of Death" (note: say that the voice over guy for a really bad 60's "tales from the edge of the Universe" show). */me goes looking to buy a new computer *sigh*.

(https://www.katsbits.com/images/blog/nvlddmkm.sys-blue-screen-of-death-error_sml.jpg) (https://www.katsbits.com/images/blog/nvlddmkm.sys-blue-screen-of-death-error.jpg)
Blue screen of Death on a Fujitsu Xa2528. Need a new PC :o
Title: Re: Faulty hardware, nvlddmkm.sys & the BSoD
Post by: ratty redemption on October 05, 2011, 01:45:02 AM
sorry to hear of your laptop dying, that really sucks my friend. have you chosen it's replacement yet? and is it possible for you find out about the build quality before your next purchase?
Title: Re: Faulty hardware, nvlddmkm.sys & the BSoD
Post by: kat on October 05, 2011, 03:34:23 AM
I'll probably being going back to a desktop (looking at a Shuttle based small form factor system at the moment). Laptops are OK but you do tend to be holding all your eggs on one basket for the sake of the more convenient format (monitor and PC powered by the same source). In addition to that, sadly (or more appropriately 'deliberately') the notebook industry doesn't really want users looking under the hood of their hardware so there's no real way anyone can vet a system beforehand unless it's been out for a while and search results are available - people posting their experiences.
Title: Re: Faulty hardware, nvlddmkm.sys & the BSoD
Post by: ratty redemption on October 05, 2011, 04:01:21 AM
understood and interesting, i've not researched much into sff systems before, so will be looking forward to hearing how you get on with one, would you say their cooling designs are better than laptops for gaming and other 3d intensive apps?
Title: Fixing broken laptop heatsink
Post by: kat on October 07, 2011, 10:00:25 PM
Well... the temporary fix was to jam some paper wads between the heatsink and outer casing to push with enough pressure downwards to at least seat the sink plates onto the GPU chip properly. Not ideal but works for now, at least the ships are getting a modicum of proper cooling.

(https://www.katsbits.com/images/blog/fixing-laptop-heatsink-jamming-paper.jpg)
[temp fix uses paper to push the heatsink down using the case as fixed point of contact]

Ideally it would have been much better to have been able to re-solder the mounting pots back into the motherboard but using a traditional soldering iron risks damaging other areas of the board because you can't generate the right amount of heat quickly enough to melt the solder, fix the pot and not overheat the surrounding board - why they use robots and electro-conduction to effectively 'spot-weld' joints; it keeps the heat generation extremely localised.

(https://www.katsbits.com/images/blog/heatsink-mounting-pot.jpg)
[circled area shows 'bad' connection and a lot of 'dry' areas where solder hadn't achieved 100% coverage]