Neutrino

Issue solved! Figured it's polite to actually follow up with the end result instead of leaving yet another mysteriously silent thread with no conclusion because the OP couldn't be bothered to post an update. Took the AIO all apart again (Lepa Aquachanger 240) and drained it completely except I filtered it through a coffee filter. Next I ran vinegar though the hoses and radiator and let it sit for 5 min. Let the cold plate and pump housing sit with vinegar on them for 10. Flushed with vinegar, then tap water, then did a bunch of flushing with distilled water. Quite a bit of gunk came out. Put the drained and filtered original liquid back in and topped it up with distilled water and reassembled it all. Installed it back in my tower and it's cooling just fine! Even better than pre-lapping, actually, so in spite of the problems I caused myself, I was still successful I know that putting in fresh coolant would be best, but the point of the project was to spend as little money as possible so I just put the old coolant in. When this thing dies, I'll probably switch to the Arctic Freezer II. I think what happened is that when I topped it up with distilled water the first time, I did a LOT of shaking to the hoses and radiator and ran the pump for brief 5 second intervals to get any air bubbles out. I think the combination of shaking it a lot, and running the pump multiple times, cause debris to break loose and then pile up at a single choke-point and that was killing the flow-rate. And of course the low flow-rate meant it's cooling capacity went to shit. Lesson learned!

So I decided to get adventurous and take some sandpaper to my CPU and AIO cold plate because I've never been happy with my temps. Started with 240 grit wetordry, finished with 2000 grit, on a piece of glass for flatness. The cold plate was remarkably even (check picture, no hotspots) and didn't need lapping. As you can see if the picture, the CPU IHS was convex and I took some material off. At first I thought the overheating was because water got into the small hole in the IHS and hadn't dried completely and was shorting something, but now I'm not sure. Here is the order of events so far: - Lap CPU and cold plate - Top off AIO with distilled water and cleaned out the gunk build-up in the coldplate's fins. - Resocket and repaste with IC Diamond - Replace GTX 1080 with RTX 3060 Ti - Turn on computer and update Nvidia drivers first thing (was 2 updates behind) - Fans start ramping to max towards end of update - Computer starts shuddering and crashes within 15 seconds of stuttering starting - Try turning back on, shuts off within 2 seconds of pressing power button. - Wait a few min, try again, POST displays CPU overtemp warning. Shut down and wait 20 min to cool down more. - Turn on and go into BIOS. CPU temp starts at 70⁰C and steadily climbs to 85⁰C in 2 min. Shut down for the night. - Next day, same behavior - Take CPU out, clean off and put distilled water into the IHS hole. Used hair dryer to dry it out. - Next I put isopropyl alcohol into the hole, and used the hair dryer again. - Resocketed, repasted and changed back to my GTX 1080. - Temps in BIOS are now stable at 33-35⁰C, figured the problem was solved at this point because before this it would overheat even in BIOS. - Boot into windows, CPU hits 90⁰C within 3 minutes, except it doesn't crash. Downclocks to 400MHz and everything is slow as hell, but doesn't crash. I shut down after being on for 10 min. So this is where I'm stuck. I don't know why it was overheating in OS and BIOS at first, but now after trying to displace any water that may have been in the hole, it only overheats in the OS. Anyone have any ideas or suggestions? already have another 5820k order from ebay but I'd like to explore what is going on with this one.

- Open nvcplui.exe (Nvidia Control Panel, not Geforce Experience) - Under the "Display" menue on the left hand toolbar, go to "Change Resolution" - In section "3" make sure "Output Dynamic Range" is set to "Full"