PC won't boot after buying a new graphics card

[Robotmood]

Specs:
CPU:Intel I5-2400 3.10GHz
RAM:4GB DDR3
MotherBoard:Gigabyte GA-H61M-S2PT
PSU:300W Mercury
OS:Win7 64bit
GPU:Zotac GTX 1050ti 4gb low profile

Hey everyone,

So I just bought and installed my new graphics card GTX1050 ti 4gb (low profile), after fitting the graphics card onto the board i tried to start up the PC and nothing happend the monitor just shows a black screen like there is nothing connected to it(there is a signal), and also there is no response from the mouse and the keyboard. When I turn on the both the CPU and GPU fans are spinning with no problem, but the monitor power light are just flickering(as if the PC is in sleep mode). I removed the graphics card to test out the PC without it, and even without the graphics card I got the same problem. I Tried to unplug the power, remove the RAM, and reset the CMOS but nothing worked.
My motherboard never beeped from day 1, so I wouldn't know about that.
The PC was working just fine before turning it off before I go to the shop.

 

[DSzymborski]

How many amps on that +12V rail? It should say on the side of the PSU. I'm detecting the distinct aroma of a garbage PSU.

 

[InvalidError]

My initial guess would be crappy no-name PSU as well.

 

[Robotmood]

How many amps on that +12V rail? It should say on the side of the PSU. I'm detecting the distinct aroma of a garbage PSU.

On my PSU the 12V+ rail is @12A. It's a stock PSU but even when I tried to revert back to use the computer without the graphics card it's still not booting up. Does that mean my PSU is fried? And will switching the PSU fix the problem?

 

[InvalidError]

Only 12A on 12V? That's only 144W. Not enough to run the CPU, GPU, fans, HDDs and other stuff that runs primarily off 12V even on a good quality PSU. You need at least 20A there and even that would be uncomfortably tight ON A GOOD PSU.

You need a better quality PSU with higher 12V rating. Preferably over 25A total on 12V.

 

[DSzymborski]

Yup, there's the problem; you have a PSU that for all intents and purposes is a 144W PSU. You had a 95W CPU and added a 75W GPU and, well, do the math.

Your best case scenario is that your PSU is fried and took nothing with it. The worst case is that it took more. You won't know until you replace it with a proper PSU. Unfortunately, the purchase of this PSU and the purchase of the GPU to use on this PSU were both poorly considered decisions.

 

[Robotmood]

Only 12A on 12V? That's only 144W. Not enough to run the CPU, GPU, fans, HDDs and other stuff that runs primarily off 12V even on a good quality PSU. You need at least 20A there and even that would be uncomfortably tight ON A GOOD PSU. You need a better quality PSU with higher 12V rating. Preferably over 25A total on 12V.

Alright, so I'm planning to get a PSU with those specs to run everything including the GPU. But what I don't understand right now is why my PC isn't booting even though it used to boot just fine prior to the GPU installation.

 

[DSzymborski]

Only 12A on 12V? That's only 144W. Not enough to run the CPU, GPU, fans, HDDs and other stuff that runs primarily off 12V even on a good quality PSU. You need at least 20A there and even that would be uncomfortably tight ON A GOOD PSU. You need a better quality PSU with higher 12V rating. Preferably over 25A total on 12V.

Alright, so I'm planning to get a PSU with those specs to run everything including the GPU. But what I don't understand right now is why my PC isn't booting even though it used to boot just fine prior to the GPU installation.

You had a junk PSU that was just barely powering your build. Then you threw an additional 75W GPU on top of all that. It's the equivalent of deciding to tie a grand piano to the roof of your Volkswagon Beetle from 1975.

 

[InvalidError]

But what I don't understand right now is why my PC isn't booting even though it used to boot just fine prior to the GPU installation.

There are three possibilities:
1- your overloaded PSU died
2- your crappy PSU fried your motherboard and possibly other components
3- both

You have just learned the hard way the main reason why you should never buy generic unknown quality PSUs.