Desktop going off under extended use of power

Saxicolous

Reputable
Jun 26, 2014
19
0
4,510
Iv'e had this problem for quite a while when i first built this desktop , after like a couple months of construction this problem introduced itself. It would turn off only after extended use of power or sometimes just random.After the computer turns off , it would just turn back up normally like a restart. I know this problem is got nothing to do with the house electricity but the actual computer itself, im not quite sure what to do to resolve this problem.

When i web surf on my computer it doesn't randomly shut down but only when i use a game for some cases (30-40 min)a short time or (5-hours) extended use. It can even shutdown when i use the computer for a really long time around 10-hours .
my specs
Graphite series 730t
Thermaltake Smart Power 750W 80 Plus Bronze
BitFenix Spectre Pro 120mm Black Tinted Red LED Fan
Thermaltake NiC F4 CPU Cooler
Intel 530 Series 120GB SSD
Seagate Barracuda 1TB ST1000DM003
Gigabyte GeForce GTX 770 OC Edition 2GB
Intel Core i5 4690K
G.Skill F3-14900CL9D-8GBXL 8GB (2x4GB) DDR3
Gigabyte GA-Z97MX-GAMING 5 Motherboard
The only thing i know that might resolve the situation is either get a new psu or get a psu so it goes into another power generator when it goes off.
Please a solution would be appreciated :)