Question GTX 980 Ti Black Screen of Death

[Staskw]

my 980 Ti is underclocking by itself to 756- 886 max MHz instead of 1350 that used to be.

FPS drops about 20-30% and eventually games are crashing with a black or white screen of death.

Same card on a different system happens the same with Purple Screen.

Opened the card,changed the paste but still the same issue.

The card has never been overclocked,is it dying?

 

[sdedu77]

It might be sufferning from thermal throttling. Please list your entire components; also, don't forget the temps.

 

[Staskw]

Operating System
Windows 10 Education 64-bit
CPU
Intel Core i5 6600K @ 3.50GHz 27 °C
Skylake 14nm Technology
RAM
16,0GB Dual-Channel Unknown @ 1200MHz (14-16-16-31)
Motherboard
Gigabyte Technology Co. Ltd. Z170-HD3P-CF (U3E1) 30 °C
Graphics
LG IPS FULLHD:€q8-@X,E (1920x1080@75Hz)
2047MB NVIDIA GeForce GTX 980 Ti (Gigabyte) 40 °C
Storage
232GB Samsung SSD 850 EVO 250GB (SSD) 28 °C
PSU
Corsair RM750x

The above are idle temps.
GPU temperature after new paste wont go past 65 celsius while gaming and suddenly boom Black screen and I cant do nothing but to turn off the PC from the case button

 

[uppercut4u]

Check DDR settings in mobo Bios try default settings or auto. check CPU temps, GPU temps at idle and under load b4 crash?

 

[Staskw]

Check DDR settings in mobo Bios try default settings or auto. check CPU temps, GPU temps at idle and under load b4 crash?

CPU Temp didnt rly noticed a spike in temperature.
GPU Temp before thermal paste change was approx 81 Celsius under load (Edited: In the last crash clock speed was normal so I dont know if core clock was the problem after all).
DDR Voltage is at 1.20V if thats what you mean,I dont understand what this has to do with the card giving black,white and purple screen of death on two different systems.
This happens only in games and not on benchmarks(Superposition,Heaven,Valley,Sanctuary and Furmark) although my score in all of them is too low for my specs.

 

[Staskw]

bump

 

[Staskw]

bump