[P775DMG-3] Graphics card problems after Liquid Metal Repaste

So I just de-lidded my CPU and re-pasted it and my GPU with conductonaut but unfortunately I seem to have damaged something. Applying the paste its self was actually pretty straightforward and I don't think I made any mistakes.

What ended up being a nightmare was getting the heat sink off... a couple of the screws completely stripped on me and I was forced to cut a slot for a flat head into them with my dremel. I covered the rest of the laptop with paper towel, making a small hole where the screw was and filled around it with blu tac in an effort to prevent any metal shavings getting anywhere but I'm sure some of the fine dust got to some places (I've gone over the whole graphics card and mobo with a small brush and vacuum). Also I noticed I managed to nick the very corner of one of the grey square inductors.

Anyway, basically after putting it back together and booting it up I ran CPU stress test and was delighted to see everything seemed to be working but then as soon as I launched a game the screen went funky and then the signal to my screen died. Sometimes the whole system will shut off sometimes it just stays frozen like that. It will run for about 20 seconds before it crashes, and during the time the temps seem good.

On battery it will actually run stably but at a very low and inconsistent clock speed (i don't know if that's normal on battery).

On a few occasions after crashing I've rebooted and found that the laptop is no longer charging and looking at the AC brick I notice its led indicator is off, I have to unplug the whole thing from the socket and plug it back in for it to start working again...

Is it possible it's actually a problem with the AC adaptor that is causing the graphics issues? I'm not sure how that would have gotten damaged. I suppose if the graphics card is damaged it could have over drawn and damaged the PSU too? I've ordered a replacement to test anyway...

Sorry for long post, I wanted to be get all the details. Wondering if any of you guys have any ideas on exactly what has gone wrong.

Cheers,

Edit: To clarify the system is totally stable with low GPU load. It is only crashing during 3D rendering (video games, GPU stress tests etc.)

 

I'd remove the conductonaut from the GPU and use a normal paste (your heatsink maybe sitting a bit high for the LM to make decent contact to the gpu die). And check the thermal pads are in place/intact.

 

It's more likely for the vacuum to damage something due to the static it generates.

 

I did wonder about that, but the temps before it crashes seem fine. I guess it's worth a try though.

I didn't hold the vacuum close at all, was just there to catch any dust the brush kicked up.

 

Were you grounded with a strap at the time?

 

Yup.

 

aziraphaleUK was right! It seems it was a contact problem. I tried out the paper clip mod on the heat sink and so far so good; 7 minutes into Kombustor and no issues!

 

Good to hear the paper clip mod has worked and appears to be just a contact issue. I wouldn't run Kombuster for to long thou.

 

Ran it for about 10 minutes and booted up a few games for a little. Was crashing within 30 seconds before so seems good!

 

Glad to hear its behaving better. Worth keeping an eye on the thermal pad contact too.