No power - 4090 - 5900x

energizer123 · 30 Oct 2022 at 18:14

Hi all,

Really need help - anything would be very much appreciated

Moved everything over to a new case loan li 011 xl and got a new 1200 w psu.

Thought the build went fine. Press on and I have no power. Nothing, no lights on mobo power button does nothing.

Checked following.

Plugged in all old psu same problem.
Checked all connections everywhere. All in.
Checked wiring to power switch it’s there.
Checked it’s on at back (psu)
Checked plug and cable woek

I have no idea.

Help please!

Thanks

energizer123 · 30 Oct 2022 at 18:22

Gutted doesn’t come close

lsg1r · 30 Oct 2022 at 18:38

Have you tried taking out the cmos and putting it back in?

Are you 100% on the cables

Did you try the paper clip trick on the psu

Is the plug (socket) turned on

Has it tripped a fuse without you knowing

energizer123 · 30 Oct 2022 at 18:44

Build 15 plus pc’s never had this. Gutted.

1000 percent on cables, changed cables. Triple checked all pushed in for a click. Just trying mother board and cpu to try and get a light, nothing.

Plug - I’ve tried a lamp in. Workinf

What’s the paper clip trick. I need to try cmos too

energizer123 · 30 Oct 2022 at 18:53

Jumping the pins on the mobo doesn’t work. I literally have no clue.

lsg1r · 30 Oct 2022 at 19:34

energizer123 said:
What’s the paper clip trick.

Plugging a paper clip into the psu cable to see if the psu fires up....basically the below
https://www.silverstonetek.com/upload/downloads/QA/PSU/PSU-Paper Clip-EN.pdf (pdf but it's safe, direct from silverstone site)

Could try reseating the cpu and cooler, read something about pressure/fit stopping a pc loading up before but I'm edging towards a dead motherboard if I'm honest.

wookiee87 · 30 Oct 2022 at 20:04

if all above fails take you pc fully out of the case and run on the motherboard box, if suddenly you get a power on then i'd say somehing in the new case is shorting out on the motherboard, check standoffs and remove any that dont line up with you motherboard holes.

you can take the 4090 out too anmd see if everything turns on if it does maybe somethings up with the gpu?

Haz123 · 30 Oct 2022 at 20:27

I would suggest you take the motherboard, gpu and psu out of the case . Remove the cpu from the socket and check for bent pins and if it is ok carefully reseat the cpu into the socket then rebuild the rest of the PC on a box and see if it has power outside of the case.

I assume this is a B550 or X570 mobo? If it is an older mobo like B450 it would require a BIOS update to recognize the cpu.

wookiee87 · 30 Oct 2022 at 20:29

Haz123 said:
I assume this is a B550 or X570 mobo? If it is an older mobo like B450 it would require a BIOS update to recognize the cpu.

if that was the case the pc should still power on but give no output, the op's pc refuses to turn on which indicates a diffrent problem

Haz123 · 30 Oct 2022 at 20:37

wookiee87 said:
if that was the case the pc should still power on but give no output, the op's pc refuses to turn on which indicates a diffrent problem

Yeah I know, I was jusy trying to politely get the OP to let us know what mobo it is. I firstly suggested the same as you , rebuild PC outside of case.

I bent the pins on a 5900x when putting it into the mobo and it exhibited the exact behaviour as energizer describes so I fear that may be the situation. If it is then do not panic , I managed to repair the pins and my 5900x is working just fine.

One other thing I should have recommened is, do you have another gpu to test with ? Just plug in any old gpu to see if you can get video out and see if the gpu is not playing nicely with the mobo. I think Jayz2cents had an Asus 4090 that just would not boot on an Asrock mobo , not sure why but it worked in other mobos np so it could just be a teething issue.

energizer123 · 30 Oct 2022 at 20:55

Sorry I should have said I just moved it from my old case phanteks evolv to the Lian li xl. All I changed was new rgb fans and a new psu.

Everything else was in my old pc working perfectly.

I tried unplugging all cables and putting back old psu with original cables. Exactly same issue.

Tried shorting power from mobo, in case on switch broken. Nothing.

Think you’re right sadly I need to take it all out and rebuild. Can I test without cooler.

It’s a 570

wookiee87 · 30 Oct 2022 at 20:59

energizer123 said:
Can I test without cooler.

you can if you must but only around 10-20 seconds max as if the pc boots the cpu will get very very hot fast, ideally to avoid killing it attach your cooler if you can, run everything out of a case and see what happens, which x570 do you have and do you know what bios version you are running, as mentined by Haze123 jayz2cents had a weird issue with a 4090 not able to display a picture but the pc booted

Haz123 · 30 Oct 2022 at 20:59

When I rebuilt outside the case with 5900x I just placed a small heatsink onto the cpu while I booted into the bios. I did not attach the cooler , it was just resting on top so be careful not to knock it off. CPU was in mid 60s when in bios so nothing to worry about. I would say you can always plug it all in and see if you have power and not even boot into bios if you do not want too.

energizer123 · 30 Oct 2022 at 21:25

Mobo is the msi tomahawk mag 570.

So rebuild it on a box, no gpu outside of case. Connect power and see if I get anything.

If not - assume mobo just broken during the transfer.

Thanks!

energizer123 · 30 Oct 2022 at 21:26

It’s not a case of no picture. There seems to be no power to the mobo at all.

Haz123 · 30 Oct 2022 at 21:29

energizer123 said:
So rebuild it on a box, no gpu outside of case. Connect power and see if I get anything.

If not - assume mobo just broken during the transfer.

No you need a gpu of some kind plugged in even if it is outside the case. If you have another gpu to test with it would be helpful.

mickyflinn · 30 Oct 2022 at 21:36

energizer123 said:
It’s not a case of no picture. There seems to be no power to the mobo at all.

That motherboard has bios flashback button on the rear io , if I rember correctly if you press it a white led will flash 3 times on the board.

Could try it see if there's any life , just connect the 24 pin and 8 pin eps power cables and push that button.

energizer123 · 30 Oct 2022 at 21:43

mickyflinn said:
That motherboard has bios flashback button on the rear io , if I rember correctly if you press it a white led will flash 3 times on the board.

Could try it see if there's any life , just connect the 24 pin and 8 pin eps power cables and push that button.

Thanks - I will try this when I’m back
from work tomorrow. If it doesn’t flash assume mobo is dead?

energizer123 · 30 Oct 2022 at 21:44

Haz123 said:
No you need a gpu of some kind plugged in even if it is outside the case. If you have another gpu to test with it would be helpful.

Just one card sadly. Will it not try and boot even without a card. Any sign of life would be a dream.

mickyflinn · 30 Oct 2022 at 21:48

energizer123 said:
Thanks - I will try this when I’m back
from work tomorrow. If it doesn’t flash assume mobo is dead?

Yes or the psu .

Would download latest bios and put on a usb stick as per manual.

Tutorial.