Hello, welcome to the EVGA Forums & Congrats on your first Thread
I agree, probably a PSU issue. Suddenly "shutting off like you pulled the plug" is classic PSU issue
Are you using Separate PCIe cables from PSU to Each port on the 1080 Ti ?
---> One of the PSU safety circuit could be tripping?
---> One of the PCIe cables might not be fully installed, locked or Bad ?
PSA: Only use cable that came WITH your PSU .... other cables ---> user MUST confirm compatibility first ---> If your PSU came with more PCIe cables or ports on the PSU ---> try different ones
PC plugged into the wall or a UPS ?
please list your Hardware:PSU, model & age
Any OC on your hardware? CPU, RAM, GPU if so what software/ settings
MB & BIOS
CPU
GPU model 1080 ti sc2, (part number?) Nvidia driver, changes in Nvidia Control Panel, OC software?
HD(s) type & connection (mechanical, SSD ..)(M.2 SATA ...)
OS
- any other items installed into the MB?
run GPU-Z & look @ sensor tab while gaming .... you can set it to record
Take your game & crank it up
because other software & games are not crashing, unlikely it is a bad mouse or KB
Your new on the Forums, so it might be helpful to know a little about your PC experience level.
We have no idea if this is your first GPU swap ever or you build & fix PCs all the time