want ot detect problem

[noxayuzi]

i had weird problem today first i was playing smooth things were will later things started to become weird my screen went off tried to fix it by pressing on the cable didn't work it seemed like thermal throttle but i didn't had that since very long time so i tried again with same game suddenly the same then restart then i tried different game lasted longer then same problem expect i couldn't restart or see thing so i turned off went to buy food went back trying to turn it on still no screen tried to fix the cable then turned it off completely push on the vga to check if anything lose slightly gentle tried again boom it turned on so my i changed the thermal paste since 3 weeks or so
my question here is what is the problem caused this

 

[rgd1101]

What is the full system spec? include make and model of the PSU

 

[noxayuzi]

i7 2600k
ddr3 8gb ram 1330mhz kingstone
motherboard gigabyte h61m-s2v-b3
rx 580 gaming x
psu Seasonic X750 750W 80+ Gold i guess it is been working since 2013
today same problem expect all i did was shut it off after i tried restart and re checking cable also i re pressed little bit on the vga if it count as pressing as i wasn't using any force at all psu temp look ok i checked it also my case is electrified so when i try to touch it feels like touching naked wire same problem tried the same things expect i run into little problem where my fan cable stuck to gpu fan until it stopped i disconnected the electricity fast to stop any damage
so could this be thermal throttling i must admit i didn't change my cpu cooling fan also i have another question is my gpu fine or did it effect it by any way cause it is in the warranty and i don't want to end up with problem out of warranty