System won't boot up - Tried RMAing the PSU already and still not working

[Linus]

This is a question from tienflame:

Hi linus im sorry for wasting your time but i just have a question i wanted to ask if you can help me solve this computer problem i have. I have been watching your videos for years and i finally saved up enough money to built my own gaming p.c.

I have just finish building it and did all the wire management but there is a problem of my computer not turning on. I thought it might have been a power supply problem and i did an RMA on the power supply but it still wouldnt turn on after i install the new psu.

I have no idea what to do now please if you can help! thank you

Also i have a
990 FX sabertooth MB
AX 850 PSU
8gb of G skill ripjaws series Ram
msi n560 twin frozr 2
H 70 liquid cooler

So are you getting any lights or fans spinning up at all? Have you checked to ensure that all power connectors are plugged in?

If you're still getting absolutely no response from the system, my best guess would be motherboard since you've already RMAed your power supply once. The odds of two dead PSUs in a row are very remote.

[LarkStarr]

also, if the motherboard does boot up, hook up the little two wire speaker to the motherboard (look in your manual) and see if you get a series of beeps, which is an error code (which you can look up also in your manual)

[tienflame]

when i built it i forgot to post it like you said in one of your videos. i will try it to see if it post or not. Also my motherboard didnt come with wire speaker. I've checked everything. Also the nothing turns on my led lights doesnt and all the fans doesnt so i dont really know wat to do. Should i just try to RMA the 990FX and start from there?

[LarkStarr]

other then checking that you've hooked up the power switch correctly, I believe a RMA would be your best solution.

[tienflame]

ok i wil check to see if i hooked everything in correctly before doing anything else

[tienflame]

ok so i check the headers, on the 24 header slot that connec to the motherboard there is a square-circuler brass/gold color thing that is missing. is that normal? if it isnt then how do i get new cord cuz i already RMA the power supply. its an AX 850 by corsair.

[SKYMTL]

It's normal that one of the headers is missing a brass connector.

[3.0charlie]

Time to install this naked, out of the case. Get everything out, and use the board's box as a temporary surface. Then use a single stick of ram, and the stock HSF for the CPU. Do not use any USB accessories (if possible). Make sure all connections are secure, and fire it up.

A motherboard on a cardboard box will look like this:

[Perineum]

Make sure that in your case there are as many standoffs installed as there are holes for mounting on your motherboard.

Typically a standard ATX motherboard will have 9 brass standoffs that install into the case for mounting the motherboard. If there are 10 installed, then the 10th will be shorting out the bottom of the motherboard causing a short that will stop the machine from powering up.

Doing what 3.0 suggested is definitely your next step.

[Jonesy]

Have you tried a second power button? While that shouldn't be the cause of the problem as they typically don't fail. However if it saves you from RMAing a good board, it is worth a shot (best to eliminate the issues which you can check yourself, before sending out all your gear to find out it was a dead switch).
Don't take this the wrong way, but have you verified the power source that is feeding the PSU to be working? IE, other accessories on a power bar work fine / tried a different wall outlet - power bar outlet?