Pc wont start/has no power

[kaolor0596]

Hello everyone,

I woke up to a completely dead pc the other day. It has no power completely (my ram's LED has no power, fan LEDs no power, motherboard LEDs no power, no power/lights anywhere). I left it in sleep mode the night before which I usually do and have been doing so for the past year or 2. 4 days before my pc died on me, it froze while I was gaming (pretty unusual and rare) and wouldn't restart/shut off unless I completely shut off the PSU. I shut off the psu, unplugged it, plugged it back in and my pc ran fine until it didn't two days ago.


At first I thought it was my PSU so I bought a new one and replaced my old one with it. Still no power or LED lights anywhere. Because my pc still had no power with the new PSU I decided to test/jumpstart my OLD PSU using the paper clip method with the 24 pin motherboard connector. To do this, I plugged into my old PSU only the 24 pin connector and a Pcie connector which I had connected to my fan speed/LED controller. Once I had the paper clip in pins 4 & 7 on the 24 pin connector, my PSU fan and my pc fans along with their respective LED lights came on so I figured my old PSU wasn't the issue. Probably should've tested it out first before rushing into buying a new PSU but whatever.


I quickly returned the new PSU and picked up a new motherboard because thats what I thought was my issue. I swapped in the new motherboard but still had no lights or power anywhere. I made sure my 8 pin cpu connector, 24 pin motherboard connector, and all of the JFP1 cables were plugged in correctly. New motherboard still in pc currently.


Now I'm starting to think it's my case? Could I have possibly have gotten a bad new motherboard? Is there a way to test the motherboard? Or should I buy a new case? Please help and suggest other possibilities! Thank you!


PC spec:
CPU - ryzen 7 3800x
GPU - 6950xt
Ram - 2 sticks of 16gb
Old motherboard - Asus Tuf x570 plus
New motherboard- MSI b550 tomahawk
Old PSU - CORSAIR 850w
New PSU - Corair 1000w (returned already)

 

[Bruce]

g'day and welcome to the forums.

my money is still on the PSU.
the paper clip test is all but useless. it simple means the unit is getting power, it by no means the unit is delivering reliable power across all the 3v, 5v or 12v rails.

by the way, list the PSU make/model as well - Corsair 850w could cover many of their products.

your next hurdle is, sometimes when the PSU goes south, it can take out other hardware, eg: motherboard, processor or RAM.

I've also seem power surges come through the phone line, rather than the power cable, and take out modems and therefore the ethernet port on the mobo.

in other words, no hard and fast set rule to follow here.
with that in mind, I would be removing all your parts and reassembling on a piece of cardboard.
I'd get that PSU back, the new mobo, and only connect the bare essentials, so one drive, one RAM stick, no keyboard or mouse, no fans, etc - at this stage we are simply trying to get the PC to boot.
if that happens, then we can attached the keyboard and get into BIOS and see what is happening.

 

[phillpower2]

Once I had the paper clip in pins 4 & 7 on the 24 pin connector,

Say what

4 is only for the +5V rail and 7 a common ground and the only way to test the PSU while it was hooked up to the hardware is by shorting out the + and - pins for the case power switch on the MBs front panel header.

New MB but same behaviour, flaky PSU or case power button.

 

[Bruce]

@kaolor0596 - still with us?