PC no longer powers on after attempt to add graphics card (fans briefly turn on and off)

[Polygon]

Two years ago, I built a PC (parts list here: https://pcpartpicker.com/user/rhomboid/saved/#view=nNJgXL), and it worked fine. However, today I decided to try to add a graphics card. Unfortunately, it no longer powers on, even after I removed the added graphics card, thus returning it to the original state.

When plugged in, the case and cpu fans briefly turn on and off repeatedly. I've tried searching online, and all the information I could find suggests that something isn't plugged in or a component failed. However, in my case, the computer has been working fine for over a year. All I did was plug in a new graphics card (and then unplugged it). I didn't even unplug the existing cables, so it's hard to believe something suddenly stopped working.

Any ideas what the best way to proceed is?

 

[Cycloid Torus]

 

[Polygon]

Update: I tried removing the RAM, and now it's completely dead, even after putting the RAM back in. The fans don't move at all. The only sign of life is a blinking LED on the front of the case.

 

[Cycloid Torus]

At this point, it could be: motherboard, cpu, gpu, ram, psu, hdd, bad 'power good', bad mouse, bad keyboard or, frankly, anything else connected to the motherboard - or not connected, if any connection is loose.

In your shoes, I would follow the steps in the video to see if 'anything' works. The best way to do that is a benchtop re-assembly as per the video. Locate a copy of the motherboard manual to help you do it according to the manufacturer's instructions. Keep good notes. Another troubleshooting schema is http://www.computerhope.com/issues/ch000607.htm.

Oh, and did I mention the video...

 

[Polygon]

I already watched the video, though most of it was irrelevant to my case.

Anyway, I tried unplugging most of those things, and there was no change. Plus it's unlikely the components are bad to begin with, since they worked previously, unless the very act of messing around in the computer fried them. The only things I didn't try unplugging were the CPU and PSU.

 

[Cycloid Torus]

"I already watched the video, though most of it was irrelevant to my case."

Video is more about a process than any specific element. It was provided as an aid to forming a disciplined approach to your problems.

Let us know how it works out.

 

[Polygon]

As mentioned before, everything I tried to do just made the problem worse. My plan now is to take it to a computer repair store and hope they can figure it out.

 

[Polygon]

The saga continues: I took it to the repair shop and it worked basically without the guy doing anything. He then installed the graphics card and rewired things to make the cables less of a mess inside the case. Unfortunately, once I got home it once again no longer works.

I thought it might be an issue with the power outlet, but I tried plugging it into the outlet in the kitchen and that didn't work either.

The real question is how it ever worked in the first place, if the apartment outlets are defective. It's possible that the graphics card is drawing enough extra power to break things, but that wouldn't explain why it wouldn't work even after I took the card back out.

I am very confused.

 

[Cycloid Torus]

Take it to a friend's house - if it works there, then you may have an issue with your electrical supply.

 

[Polygon]

Update: I took it to work and plugged it into the exact same cable and outlet that power my work computer, but there was no change. Having confirmed that the problem is with the computer after all, I took it back to the repair place, but the guy there couldn't figure it out. This time it wouldn't POST, even for him. He kept it to investigate, so hopefully he'll figure it out soon.

I'm beginning to think my computer is haunted.

 

[Cycloid Torus]

"I'm beginning to think my computer is haunted."

Nope, just flaky. Keep us posted...I've repaired 40 or so in past 30 years, and I've never heard of something like you are going thru.

 

[Polygon]

Update: I got my computer back from the repair place today. It wasn't clear what they did, but they said they just fixed up and secured some of the cable connections and the fan.

The computer at least powers on now, but the repair place seems to have accidentally taken my VGA-DVI adapter, so I can't test it further than that yet.

 

[Polygon]

Final update (hopefully): I went back to the repair place and picked up my adapter, and I can confirm the computer is now working again. While there, I talked to the guy who worked on the computer, and he said the problem was that the fan had gotten lose, causing overheating. In addition to securing the fan, he also applied new thermal paste, because the old paste had dried out.

Adding a graphics card turned out to be considerably more expensive than I expected, but at least it's over now.