Proc - i3-4130
Mobo - Asrock H81M-DGS
GPU - Palit GTX 750 StormX dual
PSU - FSP Hexa 500w
HDD - 500 g WD
RAM - kingston Value RAM 8GB

hello guys, im using this spec around 3 years. the problem now my graphic is not working. I bring my gpu to technician and he said that my card damage due to low voltage. Before this, my pc having trouble such as no display, but after switch on and off and adjusting vga cable, its working again. Can i repair my gpu, or i need to change my psu if i want to buy new gpu? My pc is working fine if i connect my vga cable to mobo.

How long u owned that psu?

ETA this week, the review embargo was just lifted yesterday night, be patient 
Yea that's the default value, still within safe range.

More or less the same, if you are thinking to swap to other GTX1060, don't do it, not worth the effect and money just for the little difference (likely none or just 1 to 2°C).

If no radiator or anything that can block the airflow (front panel) then no need to go for SP, AF is more efficient in this case.

2 AF120 for front panel, 1 AF120 on top and 1 AF120 for rear panel. Or just get 2 AF120 without buying 4 new AF120 at the same time since the case comes with 2 120mm casing fans already.

i'm using one, average temp when gaming is around 65-68c only. So far the temperature doesnt exceed 70 yet.

Check with Zotac on warranty terms. Some manufacturer are extremely strict.

Spilter is you plug more than a single fan into your motherboard hub, not advice to doing that if your total fan rating is more than 1A as the mobo fan header generally only accept below or equal 1A for proper usage.
Fan Hub is a separate device which you plug all your fans into and one of the cable is to plug on your mobo header to send PWM signal, this is powered by the PSU.

IMHO, i suggest you go for fan hub if you have more than 3 fans.

I think yours is a 3 pin, it comes with the case. So you can't control the speed via BIOS/UEFI. If you wish to do so, get PWM fans.

You can read more at  Fan Control

Software control like Asus Suite can control fans, but those are voltage controlled. Between 5v to 12v,  the software just regulates how much voltage goes to the fans to control the speed. But you need to plug in the fan connector directly to the fan header. You may use the fan spliter but it will detect as 1 fan.

IF you use FAN HUB, it will fully run the fan in full speed. Unless you get This Fan Hub, which have a switch to manually control the voltage.

Another suggestion is to swap the existing case fans to PWM ones, like the Arctic F12 or other brand you prefer.

Yes, spliter for 2 fans is fine. As long is within 1A.
May I know your budget for case fans, because there is other fans perform better than this. Because that's a 3 pin, as might well get a 4 pin PWM fans.

CRYORIG QF120 Balance 120mm PWM fan < RM 49 each you may get from linglong.