computer keeps shutting down

i recently got a new video card & after that I started getting a warning 3.3v voltage 3.774. then it started shutting down, which seems weird to me. does anyone know whats going on with my pc ?

Do you have a powerful enough power supply for your new video card?

@karnis: yes

Where were you getting the warning? what gpu is it? what psu do you have and what is the amp value on the 12v rail?

If your voltage is jumping around, your PSU maybe bad.

Try a PSU voltage tester.

http://www.amazon.com/Coolmax-Power-Supply-Tester-PS-228/dp/B002R06PGE/ref=sr_1_1?ie=UTF8&qid=1411328744&sr=8-1&keywords=coolmax+PSU+tester

It's cheap and handy. That way you can better troubleshoot it.

Your PSU capacity must be low, it's time for a new PSU.

But what GPU did you get? what's your current PSU capacity? and if you could tell us CPU module that would help.

I have a r9 280x & a 750 watt power supply. my cpu is a fx 8320

@karnis: You can check your volts with software but it's not as accurate as hardware.

Here is a chart to guide you.

Try to reset CPU if it's OC just set it to default.

did that 2 days ago. could my video card be plugged into the wrong spot on the psu

You need 1x 6pin and 1x 8pin connectors - that's it.

Wattage isn't everything

Make/model of the PSU?

You'll always need more power than what you think because when the pc is under load it sucks in more electricity. Switch to the other card, if your system stabilizes then you need to upgrade your PSU. Get a Zalmann or Therale take. Look for dual +12 v rails @ 20 amps or more. Or a single powerful amp. www.newegg.com is my prefer site of choice. (Read the reviews) Zalman, thermaletake, and cooler master are strong brands.

turns out my psu is defective . my psu is from xfx, but i'm switching brands

I figured it was a PSU. Go for Antec, EVGA, Corsair, Seasonic or Rosewill PSU.

Best bet with Antec, SeaSonic and Corsair, you might go with CoolerMaster and EVGA as well but the 1st three brands are the most popular.

@karnis: I would recommend Seasonic. If you got the cash get a platinum PSU.

Used to build a lot of systems with Corsair PSU's because they were cheaper and Seasonic was said to have made them for Corsair.

But now the price gap has come down and Seasonic PSU's are much more affordable. So now all builds I do use them.