Newly built pc won't turn on


I've just built a pc, but it won't turn on. The only thing that lights up when I plug it into the wall is an LED in the front IO. This LED also stays on for a while after turning the PSU off again... Besides that nothing happens at all when I press the power button: no fans, ... nothing, it's a lifeless pc.

I've tested other ram slots, replugged the 8 pin and 24pin connectors, an other psu, double checked the front io connections...

There are also no lights lighting up on the motherboard. Like it gets no power? (Still the pwr LED lights up in the front as soon as the pc is plugged in the wall)

Could it be a bad powercord or a dead motherboard out of the box?

I dont know what to do anymore...

MSI b150 pc mate
Core i5 7500
Crucial lpx ddr4 2133 ram (2x4)
Psu: Seasonic 520w psu
Gtx 1060 3G

I need help fast!

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Clarification Request
Did you try it without?

A lot of things. We don't need the ram, GPU or drives for a power up test.

We don't need a case either.

As to connections, we only need one. The Power On connection.

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I've tried kth only:
Psu, cpu, ram and screen.
No sign of life...

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I'm having to guess what kth is.

Keyboard? Tile? Holes? I'm a bad guesser.

OK. when it's this dead I have to pull the PSU and try the Green Wire Test (google that.)

But first I look for extra mounting studs under the motherboard and if there is any jumpers misplaced. The power on button could be non-operational so we use a screwdriver blade or other jumper to be sure it's not something simple.

This usually happens most often on motherboard replacements or when someone build the machine all in one go. Start small, without a case, on cardboard.

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I meant 'with' instead of kth

I've tried to boot on top of the morherboard box. I've also tried another (100% working) psu from another Psu.

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I can usually power up on the motherboard box with

3 parts. PSU, motherboard and CPU+HSF. If that fails I'm looking at the bad or misconfigured parts. I use my pen tip (it's metal) to close the power on pins.

No case, just 3 parts and a pen for me.

Post was last edited on August 27, 2017 10:01 AM PDT

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That fails too

I know the cpu is good for sure. I've tried a working PSU... Could it be the PSU power cable? That's the only thing i haven't tried yet.
I guess the MOBO is bad out of the box?

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you sure the cpu is installed correctly? Lined up the marks?

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Worth a look again.

The criteria for the socket is perfection.

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The golden triangle is aligned with the one on the cpu :/

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Then time for the last test.

Just PSU and motherboard, nothing else on cardboard and the pen tip or what you use OTHER THAN THE POWER BUTTON to call for a power up.

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Motherboard with cpu in it right?

I think I dont understand you completely...

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When I can't get the 3 part test to power up.

I go for a 2 part test.

By now I think but am not sure if you got it down to the usual 3 part test.

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So mobo without CPU?

(See title)

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So mob without CPU.

Did that work or not? I can't tell if you've been following directions so here's the deal.

You reduce it to smallest number of parts and when that won't power up, it's one of those parts.

Some parts like the PSU have what we call the Green Wire Test (google it) and you need a Volt Meter to really check it out. To test the motherboard you need a good motherboard. One will work, the other won't.

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It gives Some kind of power

The psu gives Some kind of power since the power led of the case lit up... I have tested that witout cpu, still no power going through.
Also no lights on the morherboard...
I still think the problem lays with the mobo or psu...

Could other parts be damaged by a bad psu?
Because Seasonic is a Good psu brand right?

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Could parts be damaged by a bad PSU.


As to the good psu question, they made millions but that doesn't tell you if the one you have is good or not.

It appears you've done all you can with what you have. A repair counter might be your next move if you can't replace parts.

Post was last edited on August 28, 2017 7:35 AM PDT

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Video if that might help.
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That cleared a few questions up.

But next, turn the phone for a better video.

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There not really much else to show

what else do you need to see?

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That shows us what does not work.

You're done to just a few parts and for most only the PSU can be tested on its own (green wire test with any load such as old motherboard you can live with burning out and a Volt meter.)

I see a CPU in the socket so the last possible move is no CPU.

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Done that

Measured the with a multimeter, everything gave the right voltage. Tried Without cpu..
dead mobo?

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Sounds like it.

Your video moved off the CPU fan when you used a key to power on so I couldn't see if it twitched. For such videos landscape mode.

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I did not move at all

Done multiple Attempts... Happy

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The youtube shows the camera moved off the fan.
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Yeah, ive read that
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That means the motherboard never sent the power on to the PSU (that green wire!)

As to the 3V battery, my criteria is 3.0 and no lower.

-> Looks like the motherboard has a deep issue. Or you are not shorting the right Power On pins.

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Greenwire test was a succes

I've shorted the right pins. Tested psu with multimeter and paperclip. Both worked.
Still wondering How It could be this dead!

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Greenwire test

Tests the PSU. It tells us the motherboard never sent the power on signal on the green wire.

I take it that the CPU out test is done so where is your new motherboard to test with?

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Thanks for everything, you're awesome

Im gonna look for an old pc that we dont use anymore tommorow, ill plug the psu into that one.

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Let's repeat a check. What voltage is the CR2032 at?

And is the CMOS clear jumper (it can be named differently and I'm not going to pull up the manual just for this one) in the right position?

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