Power supply wattage calculations?

So, I built this computer month's ago for a client who wanted a fast machine for video editing, photo work and just general computing. She also didn't want it to completely break the bank. Since delivery, it's been nothing but trouble (kernel power failures, WMI errors etc.)

Here are the specs:

(motherboard)Gigabyte LGA 1150 Intel H81 (USB 3.0) mATX motherboard GA-H81M-HD3 Intel Core i5-4690K Processor (3.5 GHz Quad-Core)
(RAM) Crucial 8GB (2x4GB) DDR3 RAM
(graphics card) Nvidia GeForce GTX 750 Ti FTW (EVGA)
(power supply) Corsair CX 430 Watt PSU
(storage) 512GB SSD
(DVD/CD drive) Asus DVD-RW [24B1ST]

Here's the thing. The computer stopped having kernel power failures and blue screens after removing the graphics card. The graphics card is flawless in any other system. So It was determined by a third party that the graphics card is drawing too much power for the PSU to keep up.

I performed PSU wattage calculations before the build, and again now. Even with the card, worst case scenario, the machine would pull 350 watts. Thats with everything pegged at 100%. There is still a 70 watt headroom there.

I believe that the PSU is underperforming.

Thoughts?

Ya doesn't the 750ti only draw power from the PCI-e slot? The power supply is probably just defective or it isn't outputting enough at base so.

This would be my recommendation for a replacement, 70 bucks, 550W, gold and fully modular
http://www.newegg.com/Product/Product.aspx?Item=N82E16817182321&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-PCPartPicker,%20LLC-_-na-_-na-_-na&cm_sp=&AID=10446076&PID=3938566&SID=

Also in that orginal build was like the 512gb ssd a requirement? Because you probably coulda gone with an i7 in that build with a 240gb SSD instead.

http://www.corsair.com/en/cx-series-cx430m-modular-atx-power-supply-430-watt-80-plus-bronze-certified-modular-psu

+12v 384W also case fans pull some power

Yeah, she wanted a high capacity SSD.

Im 90% sure that the psu is at fault here - just faulty. That model provides more than enough output for that system btw.
Just out of interest why an oc'ing cpu and a low end non-oc board?

I'm also curious as to why you chose the 4690k.

That board, with its 2+1 phase, would have been perfect for something like an i5 4460. And that would have freed up $60..

The 4690K was on sale at the time, and the price difference was negligible, so I opted for the faster part (it was like $5 more dollars)

There was one 120mm case fan (exhaust), so the additional load from one singular fan is extremely minuscule.

In that case you need a more powerful psu , the point is it doesn`t deliver 430 watts on on +12v rail (cpu,gpu), i linked corsair page but there is a chance you got even older revision which is 336 watt on +12v rail like this one http://www.hardwaresecrets.com/corsair-cx430-power-supply-review/6/

always check full spec of psu rather the watts on the box

edit:more reputable source/link http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=214