[SOLVED] Sudden loss of image on demanding apps, and computer hungs - force shutdown.. (Troubleshoot help request)

[csf91]

So this started to happen a while ago, and thought was a 'common' TDR issue, but recently it got worse, the thing that made me ask this question was that under low load, my computer works completely fine, but when i.e run an application that puts my gpu and cpu to max. performance, it freezes, or losses screen image, and no way to recover from it but to force shutdown and boot again. Rinse and repeat.

Used the PSU Calc and here's the result
Gigabyte GA-Z77-D3H
Intel Core i7 3770
EVGA GTX 970 FTW ACX 2.0 (Specs here)
3x 4GB DDR3 @ 1333
2x 7200RPM HDD
2x USB 3.0 HDD
1x USB 2.0 BT Dongle
Steelseries Arctis 5 RGB Headset
Logitech G15 Keyboard
Steelseries Sensei RAW Mouse

Tacens Mars Gaming 700W - about 5 years old (?) also the powerline here there's times it's a lot unstable so maybe affected it or just decayed over time(?)

I'd say it's PSU issue, but wouldn't the computer as soon as there's lack of power just shut down? why the loss of image and being unable to close the hung app like if O.S. froze aswell? (even tried connecting through remote desktop to double check if O.S. hung or not and if didn't close the hung app, but got no luck any single time).

PS: This is my very first thread, read the guidelines and did my best to follow them, in case i've missed something or need formatting, just tell me and i'll do asap

Edit: Found the issue, as suspected was PSU fault, but didn't knew it could do this (loss of image output while also getting the O.S blocked, instead of shutting down automatically)

 

[PC Tailor]

wouldn't the computer as soon as there's lack of power just shut down? why the loss of image and being unable to close the hung app like if O.S. froze aswell?

Funnily enough I was just reading this before I saw your edit.

Absolutely this seemed like a PSU issue (it could have easily been drivers or temperatures also) but a faulty PSU as you have now seen, can perfectly cause those problems, as it might not have a "lack of power" entirely, but the regularity of the power can be unstable or equally not putting out enough power to maintain any load on components (Amongst other things).

All I would add, is I've never heard of Tacens Mars as PSU manufacturers, and I've never seen them on any tier list, so if you replace the PSU, I would replace it with a well known and good quality PSU.

Either way, glad you got it sorted

 

[csf91]

+1 to that, unfortunately back then didn't had the knowledge so all good, i'll probably get a BitFenix Whisper M 80 Plus Gold 750W Modular, since found a good offer (new one) wich if i'm not wrong is a Tier1 PSU, and will also help with cable management.

What got me confused were the benchmarks i did, it passed literally everything, but i've now noticed why.
I've stressed separately things, I.E, CPU, later GPU, later RAM.. even did some 3d mark bench before the issue happenned this often.. it passed everything, temperatures were good aswell and it got me really mad because i've never thought it's be a PSU issue, since thought that if it was, the PC would shut down, not get hung.

Thank you