Question Help! Motherboard not working with psu

Sep 28, 2019
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I recently bought a b450 gaming pro carbon ac motherboard and I also have a EVGA supernova g3 750 power supply that came with a testing piece to show that it worked, the power supply works with the tester but not the motherboard. Is this a problem with the mother board or is it something else?
Thanks beforehand!
Ps:this is my first time building it so it may be a problem with installation but I’m thinking it’s not
 
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What makes you think it doesn't work?

Is anything lighting up?

Do fans come on at all?

Have you tried RE-seating the 24 pin ATX connector?

Double checked that the memory and graphics card are all fully seated?

Are these BOTH new, never before used, or have they been used on previous builds at all?

What CPU are you using?

What memory?

What have you done to determine that it isn't working?

Have you connected the front panel switch to the board?

Have you connected the 4+4 pin EPS 12v connector for the CPU power to the board?

Check EVERYTHING indicated here:

 
What makes you think it doesn't work?

Is anything lighting up?

Do fans come on at all?

Have you tried RE-seating the 24 pin ATX connector?

Double checked that the memory and graphics card are all fully seated?

Are these BOTH new, never before used, or have they been used on previous builds at all?

What CPU are you using?

What memory?

What have you done to determine that it isn't working?

Have you connected the front panel switch to the board?

Have you connected the 4+4 pin EPS 12v connector for the CPU power to the board?

Check EVERYTHING indicated here:

Nothings lighting up
No fans work
If by reseating you mean taking it out and trying it again then yes
The two are properly in
Both new and never been used
Ryzen 7 2700x
2 16 gb ram sticks from tridentz
I’ve got it plugged in out of the case with the 24 pin connected as well as the graphics card and cpu, nothings happening
As i said it’s not in the case so I think that part doesn’t apply
My motherboard has a half of a 4+4 pin and a 4+4 pin in the motherboard but still nothings working
 
And how are you triggering the PSU on? Are you using the case switch? Are you jumping the pwr + and - on the motherboard? How are you turning it on?

Is the CPU cooler installed and connected to the CPU_FAN header?
I’m not quite sure what you mean by that but I have it connected to an extension cord, I don’t have it by the case rn as I’m trying to troubleshoot and it has two switches, ones the | and o and the others on and off I have it on on and o, I’m not sure if that’s what you meant but I’m trying to learn right now so I’m having a bit of trouble
 
That's your problem. You have to "turn on" the motherboard. You either need to short the pwr pins on the motherboard OR connect the case switch, to trigger the system to come on.

https://www.gamersnexus.net/guides/2011-jumping-a-motherboard-without-power-switch-button

Just "turning on" the power supply, does nothing, except make it ready to be triggered on by the motherboard or the power switch on the case.
I’m pretty sure I did it as the video explained and nothing happened, should I send the motherboard back
 
Actually, since you've already bench tested it, there's really not much else you can do. Either the CPU is incorrectly installed, the memory is not installed correctly or is faulty or the PSU or motherboard are faulty. Since the PSU at least turns on when you use the tester I'd guess you're most likely issue is a bad board.

Seems pretty unusual though that NOTHING happens when you trigger it on. You do have the PSU turned on in the back, to the "I" position, when attempting to trigger on the motherboard, yes?
 
I installed the cpu with the arrows both pointing the same way, the memory was placed correctly as the clicks were on both sides of each ram stick, I don’t think it’s the psu either.
I’m going to send the motherboard back and see if that helps.
I’ve tried the psu with it on both sides and nothing has happened
 
I'll be honest, I don't know what the hell you are talking about when you say "tried the PSU with it on both sides" or "the clicks were on both sides of each ram stick".

Maybe the problem is a language barrier and you are not actually understanding how everything needs to be done? Anyhow, I guess if you get another motherboard and have the same issue you'll know that the problem is something OTHER than the motherboard.
 
I'll be honest, I don't know what the hell you are talking about when you say "tried the PSU with it on both sides" or "the clicks were on both sides of each ram stick".

Maybe the problem is a language barrier and you are not actually understanding how everything needs to be done? Anyhow, I guess if you get another motherboard and have the same issue you'll know that the problem is something OTHER than the motherboard.
Sorry bout that but what I meant was that that I tried to turn the motherboard on with both the o and I switch but it didn’t work and what I meant by the ram sticks was I installed the memory so that I heard the compartment click into place to tell me it was secure
 
Ok.

So, you DID jump the pins on the motherboard then using a flat tip screwdriver or something similar to trigger on the motherboard? WITH the power supply turned on in the I position?
Yeah I just tried it and now all the ram sticks and the motherboard have lit up I assume this means the motherboard is good but now what, should I try to make it work again
 
Yes. Install everything exactly the way it would be installed if you were putting it in the case, and then with the power supply on jump those pins. Make sure you have a monitor connected to the graphics card which should also be installed before you do this. Make sure the power supply is ALWAYS unplugged from the wall anytime you are installing or removing hardware from the motherboard. Or at least switched to the 0 position on the back of the power supply. Don't forget to flip it back to the I position when you are ready to test the system.
 
Make sure the case switch is connected to the pins you jumped.

Then see if you get an image with the GPU installed.
I’m not sure if by case switch you mean the power switch with two pins because I plugged that in and when I jumpstart it everything including the rgb fans, CPU cooler, ram, motherboard and case light up and spin but when I press the power button it can turn the system off but not on

Btw I’m using a phantex eclipse p350x case
 
No, that's not what I mean. I think you need to take this to somebody who has more experience, because it's pretty clear that you are not understanding the instructions as they are being given to you. Either that, or I'm completely unable to communicate well enough for you to understand. One of the two.

I'll try it one more time though.

Connect EVERYTHING just as you would if it were in the case.

Turn the switch on the back of the power supply ON, which is the "I" position. Then, jump the PWR + and - pins on the motherboard EXACTLY as outlined in the guide I linked you to earlier in order to trigger the motherboard on. Make sure that EVERYTHING is installed first, including the graphics card and that the monitor is connected to the graphics card.

If that is unclear, then I suggest you need somebody who has building experience to help you out.

You don't use the tester device to start the system. That is ONLY EVER used to see if the PSU is coming on, at all, so that you don't waste your time if it isn't. It plays NO ROLE in trying to get the system to power on or POST.

If you bothered to read the guide I linked you to earlier, it fully explains EVERY STEP of this process. I hate to seem old and cranky, and I appologize if I do, but this is really not rocket science.
 
No, that's not what I mean. I think you need to take this to somebody who has more experience, because it's pretty clear that you are not understanding the instructions as they are being given to you. Either that, or I'm completely unable to communicate well enough for you to understand. One of the two.

I'll try it one more time though.

Connect EVERYTHING just as you would if it were in the case.

Turn the switch on the back of the power supply ON, which is the "I" position. Then, jump the PWR + and - pins on the motherboard EXACTLY as outlined in the guide I linked you to earlier in order to trigger the motherboard on. Make sure that EVERYTHING is installed first, including the graphics card and that the monitor is connected to the graphics card.

If that is unclear, then I suggest you need somebody who has building experience to help you out.

You don't use the tester device to start the system. That is ONLY EVER used to see if the PSU is coming on, at all, so that you don't waste your time if it isn't. It plays NO ROLE in trying to get the system to power on or POST.

If you bothered to read the guide I linked you to earlier, it fully explains EVERY STEP of this process. I hate to seem old and cranky, and I appologize if I do, but this is really not rocket science.
Ok I’ve done everything correctly and the monitor turns on and everything’s running although the fans on the graphics card have stopped
Plus I knew that you don’t need the tester after you use it to see if it works I just thought that if it worked pre build then it shouldn’t be the problem with the build

Now I only have a problem with the power button on the pc, when I jumpstart it everything works but the power button can’t turn it on, only off
 

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