Wierd Freezes and black screen

[leonbajric53]

So i have dell optiplex 390 and it has an i5 2400 8gb ram and rx 550 that doesnt need any external power and it has 280w power supply, and i have that pc for over a month and everything was fine but sometimes when i slammed on the table littlebit harder pc just froze and went black screen and today when ever i play any game for more than 5 minutes whole windows freezes and after 10 seconds monitor goes to power saveing but pc is still on, and when im browsing the internet or watching youtube its fine nothing crashes, please help

 

[JamesSneed]

Download HWiNFO and see if the CPU or GPU temps are very high. I suspect you will end up needing to remount the CPU cooler with new thermal paste. Its a bit of a guess but seems reasonable from everything you have said.

 

[leonbajric53]

i checked that and when my cpu is under heavy load its aroun 58 and 62c and my graphics card is not going over 50 and i cleaned whole pc like week ago and changed the thermal paste.