is it GPU or motherboard failure?

[gizmogozmo]

motherboard - asrock a88m-g/3.1
gpu - gtx 750 ti
cpu - am fx-4350 (not sure though)

motherboard and gpu are about 2 years old, not sure about the cpu.

a few days ago my PC stopped showing anything on the monitor- it isn't a monitor issue nor is it a cable issue.

i'm thinking GPU failure because the night before this happened, i was experiencing lag in online games (but i was also streaming music and have poor wifi, and it settled a few minutes after i shut off the music) and if i left a game on its menu for a bit, my PC would freeze. there was also some weird screen cutting going on in an incredibly lightweight game, but it only happened during specific parts so i figured it was a bug? i've also had issues with audio in the past, but the monitor is about 10 years old so i never really found it weird.

mobo i'm only suspecting because one of the case fans suddenly won't turn on which also isn't broken, and that i can turn my PC on, but can't force it to shut down with the power button. however, all the capacitors look normal. but the case fan and button thing does seem suspicious to me.

i was wondering if you could tell me is it a GPU failure or if i need a new mobo? ...or both?

 

[dederedmi5plus]

• 
  ■ use multi tester to check PSU
  ■ use linux with KDE, KDE desktop environment require fast ecosystem such as yours, run any AAA games that can run in linux

If PSU faulty, consider pricey PSU, if windows faulty, do all update, if mobo or gpu faulty, start planning new build, with your budget