I also think you have to look at the graphics card as well.
Now the problem, though, could have been a power issue, like a surge of, worse, when power goes too low, which is even worse than a power surge.
If that happens it pretty well always ruins generic power supplies.
Also, unfortunately, it can ruin your hard drive, video card, and other hardware, cpu and\or mobo as well.
Now that can happen even with the pc turned off as long as the power cord is plugged into a wall outlet.
If that is the case, you may have to have all your main parts tested, or try and test them yourself.
However, i dont know if your pc was plugged into the wall socket or not before your problem happened.
Also, its smart to simply try and get the pc to boot and if that fails then do the other testing i am talking about, thats kind of a last step.
The first power supply, can you give us the make and model?
The new power supply, can you give us the make and model, please?
This can make a difference in how to approach the problem you have.
Do you have another video card you can use to see if you can get your pc to boot up?
What do you mean when you say your pc turns on?
Does the monitor show anything?
Can you get into your bios?
Do your case fans turn on?
Do any fans turn on, like the cpu fan?
What is the make and model of your mobo?
For the future, wether a power from the wall issue has caused your problem or not, can i suggest that you buy yourself an uninteruptible power supply (UPS)? A UPS can protect your pc and its parts from power issues that can and do occur at the wall outlet, issues that a simple power cord with surge protection cant handle. And they are cheap these days, you only need to buy the minimum, which is around $50 US. I can give you more reasons to get one and more info on a UPS if you want it. Again, that wont help you now but it may in the future. All pc's should be connected to a UPS and not directly to the wall outlet.