Dear forum readers,
My GTX 880M dGPU died a few months ago, and I replaced it with a 980M. Immediately after installing, I tried running a 3D game on Linux (namely The Signal from Tölva) for a good 30 minutes, and it worked well, not overheating at all. The next day I decided to update my EC+BIOS with the official EC+BIOS provided by Clevo :
KBC/EC : https://enstrong.blob.core.windows.net/en-driver/ALLBIOS/P1xxSM-A/P17xSMA_E0309.zip
BIOS : https://enstrong.blob.core.windows.net/en-driver/ALLBIOS/P1xxSM-A/P17xSMA_B0311.zip
Since then, I've not been able to use my dGPU. Both Linux and Windows crash badly within seconds whenever I try to use it. Windows sometimes BSODs with DPC_WATCHDOG_VIOLATION or completely freezes, and Linux freezes with the Alt+Sysrq key combinations not responding. The freezes for both OSes look really hard, as there seems to be no activity left at all, doesn't reply to pings, no disk activity, and of course, display frozen.
In the course of the following days I've spent a fair amount of time here, sharing my problems and trying to find solutions, to no avail. Among the nice ones who gave me a hand are two people who successfully upgraded their EC+BIOS to the latest and use a 980M without problems. One of them even has the same Clevo model as me (P170SM-A) ! I must be stupid... I was considering a BIOS downgrade as a last resort, but I wasn't wise enough to backup my original EC+BIOS before flashing, and now I can't find it (originally EC was 1.03.02 and BIOS was 1.03.03).
However, they flashed their EC+BIOS using packages provided in this thread. And comparing their files and mine, I discovered the Clevo official package additionally contains an Intel PCH (chipset) ROM flash ! So here's the difference. Had I picked the same files they did, my PCH ROM wouldn't have been flashed. I can't help thinking I've nailed it...
So here's my question : I would like to reflash my PCH to the ROM I had before or any other one that could solve the problem, but how could I do this ? I didn't back it up either, in fact I didn't even know it was going to be flashed... I could take a PCH ROM from an older Clevo BIOS package, but is that really the way to go ?
My chipset is Intel HM87 (or so says my Clevo manual).
For what it's worth, my OSes are Windows 10 Pro 64-bit v1903, and Ubuntu 20.04 (probably going to update to 20.10 soon), but I think the problem is not OS-related.
Your advices are welcome !