I am building a desktop and after assembly, the motherboard is receiving power, yet the computer will not turn on. The first time I tried it, the LED lights on the case blinked and the fan moved slowly for maybe a second, but then no power. So I assume it received a moment of power then nothing. Today I disconnected and reconnected power connections to the motherboard and now I do not even get that blip of power.

I don't want to automatically assume I have a busted power supply that came with the case, but I'm pretty much a n00b at these things so I don't want to assume anything. I am just wondering what the potential cause could be and how to test certain parts. If I need to give additional information, I can do that.

Check all of the power connections to all of your fans - CPU fan, case fans, video card fan.

The CPU fan draws power from the motherboard. The video card fan might or might not have a separate power connector, depending upon how power hungry it is. The case fans might have separate power connectors.

If none of the fans is running, then it's very likely your power supply, especially if any of the fans have separate power connectors.

If it were a bad motherboard, then one or more of the fans would probably still run.

Also, check the connections for the power switch. The connector on the motherboard is extremely small and it's very easy to plug the wrong wire into the wrong connector pin.

Even with a bad CPU and RAM, you would still see the motherboard splash screen.

It could be a few things - power supply, cpu, ram, etc.

In my experience, this is almost always a power supply issue though. If you have a spare swap it in and see what happens. (Or, goto best buy and buy one to test out - you can always return it if it doesn't work).

If you do manage to get video, run Microsoft's memory diagnostic CD to make sure the RAM is fine.

One other thing to note is that newer motherboards have 2 places where the power supply could power them.

Alright I used another power supply with a higher wattage (550W) and it blew out. The same result occurred where there was a blip of electricity, however I smelled burning this time. I am guessing something is shorting the power supply, any ideas?

Edit: I have used the same outlet twice, could I just be using a bad outlet?

I assume you mean higher wattage. 550 volts would surely blow out any power supply.

Correct, I fail at terminology.

you didn't by any chance mount the motherboard such that it's in contact with the case did you? if not, is anything metallic jammed underneath it? obv I've heard of pwr supplies dying but I don't think I've ever heard of outright destroying them, esp two in a row. there's nothing in a computer to draw that much pwr except the psu itself, feeding straight to ground; and there aren't many opportunities in a pc to do that except shorting the motherboard.

I wouldn't suspect the outlet unless you're living in a condemned building or something. except for crazy coincidence you would've had to have had clues before ever trying to put the computer together (burning smell in the wall, something plugged into the wall getting hot or failing too, etc.)

regardless, given the relative simplicity of pc parts and connectors, from what you describe it's not unlikely you have extensive damage; imo you need to have someone knowledgeable take a look at what you have there before you burn the house down, electrocute yourself, or just waste time trying to reassemble a bunch of fried parts.

Are you in the US? What do you have the voltage switch set to? 115v or 220v?