[SOLVED] Psu or cpu?

[brenen80]

Hello everyone,
So right to it.. my power went out for a few seconds the other day when it came back on my computer wouldn’t turn on at all. I thought it was plugged into a surge protector but it turns out it’s just a hub.. hard lesson learned.
So I bought a new psu, no change. I returned it and got a new motherboard. Now I have power for half a second. I read the before post form and did everything.. I tried all ram combos, breadboarded, even bought another new motherboard thinking it may have been doa.
I paper-clipped my psu and checked the voltages and the 12vs were 13 but other then that everything was right.. I didn’t check the cpu “power on” voltage because I couldn’t find what pin or the voltage was supposed to be again.
If I unplug my cpu clip from the motherboard it stays on, thus also ruling out power button.
So either my psu is faulting when it takes the cpu load, or my cpu is fried.
I’m going to go buy another psu tomorrow since i can return it and it’s much cheaper but any insight before I make the 2 hour drive to Best Buy?
Thanks

 

[PC Tailor]

Welcome to the forums my friend!

I paper-clipped my psu

This test unfortunately only tests if it has enough power to start, not if it is supplying regular and stable power of the required amount - additionally it is only a test at idle.

12vs were 13 but other then that everything was right

That is a big problem - over voltage. The 12V rail should only be 12V +/- 5%. So no more than 12.6V

What make and model PSU did you have originally?
What make and model PSU did you swap with?

This kind of problem is notorious in poor quality and cheap PSUs.
Get yourself a good quality PSU my friend!

 

[brenen80]

Welcome to the forums my friend!


This test unfortunately only tests if it has enough power to start, not if it is supplying regular and stable power of the required amount - additionally it is only a test at idle.


That is a big problem - over voltage. The 12V rail should only be 12V +/- 5%. So no more than 12.6V

What make and model PSU did you have originally?
What make and model PSU did you swap with?

This kind of problem is notorious in poor quality and cheap PSUs.
Get yourself a good quality PSU my friend!

Thank you.

Sorry I didn’t list any of my specs, i tried to do everything right and I blew it.
So this is a pre-built pc from ibuypower.
Intel i7 7700k
Originally it had an asrock b250m pro4-ib motherboard
I replaced it with an msi mpg z390
2x 8gb Adata xpg ddr4 2400 ram
GeForce gtx 1070 8gb
And the stock psu is allied 500w Max
I replaced with the 700w evga one from Best Buy but returned it after I still had zero response from the power button, not until after I changed the motherboard did I get a half second response.

I thought the 12v pins were +-10%?

 

[PC Tailor]

Thank you.

Sorry I didn’t list any of my specs, i tried to do everything right and I blew it.
So this is a pre-built pc from ibuypower.
Intel i7 7700k
Originally it had an asrock b250m pro4-ib motherboard
I replaced it with an msi mpg z390
2x 8gb Adata xpg ddr4 2400 ram
GeForce gtx 1070 8gb
And the stock psu is allied 500w Max
I replaced with the 700w evga one from Best Buy but returned it after I still had zero response from the power button, not until after I changed the motherboard did I get a half second response.

I thought the 12v pins were +-10%?

No, 5%. Standard ATX specification. EVGA Rail Tolerances
Even if it was 4.9% - I'd still be concerned, as whilst it's within spec, the variation is quite high.

What EVGA model exactly? EVGA do some fantastic PSUs, and also do some cheap and poor quality ones.

Either way, if you're reading 13V just from a multimeter (bear in mind that when you test it with a multimeter, you're only testing at idle, with no load - so usually it only gets worse when load is induced) - then the PSU needs to be returned regardless.

 

[brenen80]

Nono.. let me go back real quick. First thing I tried was the psu, I bought the evga tried it with no change then returned it to Best Buy for the sake of funds. So then I replaced the motherboard had some change (at this point I’m back to the stock allied psu) but one a second of power so THEN I tested the psu voltages. I’m assuming both my motherboard and psu went at the same time?
I’m about to drive back to Best Buy and buy the new psu again it’s just a 2 hour trip =(

 

[PC Tailor]

Nono.. let me go back real quick. First thing I tried was the psu, I bought the evga tried it with no change then returned it to Best Buy for the sake of funds. So then I replaced the motherboard had some change (at this point I’m back to the stock allied psu) but one a second of power so THEN I tested the psu voltages. I’m assuming both my motherboard and psu went at the same time?
I’m about to drive back to Best Buy and buy the new psu again it’s just a 2 hour trip =(

Either way, a PSU with 13V is a PSU that needs to be replaced.
All I'm saying is if you replace a poor quality PSU with another poor quality PSU, you may still get the same issue.

And if it is a poor quality PSU previously, there is no guarantee it didn't blow other components with it, as these kind of PSUs often do.

 

[brenen80]

Either way, a PSU with 13V is a PSU that needs to be replaced.
All I'm saying is if you replace a poor quality PSU with another poor quality PSU, you may still get the same issue.

And if it is a poor quality PSU previously, there is no guarantee it didn't blow other components with it, as these kind of PSUs often do.

Roger that good buddy. To me, this is good news because it leaves less chances it’s my cpu. I’ve been sick about this for a week now. I just kind of wanted some reassurance it could still be the psu because I don’t have 400 dollars. Thanks for your responses.

 

[PC Tailor]

Roger that good buddy. To me, this is good news because it leaves less chances it’s my cpu. I’ve been sick about this for a week now. I just kind of wanted some reassurance it could still be the psu because I don’t have 400 dollars. Thanks for your responses.

No problem at all my friend.

CPU failure is very rare, however poor quality PSUs damaging other components - that's common.
Either way, give us an update - no guarantee it will fix your problem, but the reading you had suggested it needed to change anyway. Then we can work through other possibilities, but as I said, no guarantee the PSU hasn't damaged another component.

You'll want to breadboard your PC first and see if there are any results.

 

[brenen80]

So I just got home with the new psu, same thing.... the only thing that is even consistent thru it all is my cpu at this point. I already tried bread boarding and 2 separate brand new motherboards....

 

[PC Tailor]

So I just got home with the new psu, same thing.... the only thing that is even consistent thru it all is my cpu at this point. I already tried bread boarding and 2 separate brand new motherboards....

What is your full system spec?
Assuming it was just MB, CPU, Cooler, and PSU?

 

[brenen80]

Yea, all I had connected was the mb, fan cpu. I tried with and without ram but the mb won’t even stay on long enough to display any leds aside from cpu for the split second it tries to start. I took the cpu out checked for any bent pins or anything at all and nothing. If I unplug the cpu clip the mb will stay on so I’d say now that it’s a new psu... the only thing left is the cpu. 😥😓

 

[PC Tailor]

It won't boot at all without RAM.
How many modules do you have? Have you tried a different module in a different slot?
If that doesn't work, and you've already replaced MB, then CPU must have become damaged from previous PSU.

 

[brenen80]

I mean it should at least stay turned on for longer then .5 seconds with or without ram right? It has an led for ram so I’d assume so? But either way I did try all combinations.

 

[brenen80]

I’m back with resolution. Bought a new processor and she turned right on... now I basically have an entirely new system