My friends son's X399 system has become unstable a month or so ago and they brought it to me to see if I could get it working. Specs: AMD 1950 threadripper, Gigabyte X399 Gaming motherboard, 4x8GB Gskill ram, EVGA 1080ti FTW3, EVGA 850 B3 When he dropped it off it wouldn't power on, reseated all the connections, still wouldn't power on. Hooked up a new psu and it fired right up, but it locked up on the logon screen after 5-10 minutes. Grabbed a spare SSD and did a fresh Windows 10 install and the machine was stable, ran Furmark for 15 or so minutes with no issues, ended up just letting it play some movies for a few hours before I hit the sack. Next day I get the password and hook his SSD back up and I log on and it locks up after a few minutes. Rebooted and it locked up again after a few minutes. Did a clean install of Windows on his SSD and it locked up as soon as setup was finished and when the machine restarted it was asking for boot device. Went into the BIOS and the SSD was selected as the first boot device but it wouldn't boot anymore. Did another clean Windows install and it locked up while it was doing the updates. When it rebooted it was asking for a boot device again. Now I am thinking the SSD is flaky so I grab my SSD and hook it up and machine fires up and works great. I tell him what was going on with the SSD so he decided to get a 1TB NVME drive. We install the NVME drive and install Windows and some games on it and it seems to be working so he takes it home. Next day he lets me know that it is locking up again either on the desktop while idling or when playing games. I had him remove all but 1 ram stick and move it between each ram slot if the machine crashes. crashed with each of the 4 sticks in all of the slots. He brought it by last night and tested some games to show me what was going on, Overwatch worked with no issue, 3D Mark ran fine, Furmark ran fine. GTA5 Online and this Samurai game locks up the machine. Updated the BIOS, that didn't change anything. A few hours ago I put his GPU in my PC and it worked fine. Put my GPU in his PC and it crashed to desktop with GTA online and the Samurai game locks up the PC. Also, there are no blue or black screens, the PC just freezes showing whatever was on the screen. I also noticed that the GPU is really hot to the touch. I put his GPU back in ran the Samurai game since that game loads up fast, played it till the machine locked up and touched the GPU and it was just as hot as mine was in his machine. I set the GPU fans to 100%, fired up the game and it crashed a few minutes later and the GPU was still very hot to the touch. I also tried different PCIe slots on his board as well. Is it possible that a flaky motherboard could cause the GPU to run hotter than normal? What do you all recommend?