Question PSU Bypassing On/Off...? Dead?

[narchon45]

Hi all, I have a family member building a workstation PC and I had picked out the parts when visiting - now trying to help troubleshoot the build remotely. Basically getting no action - fans don't spin on startup, no POST, but the MOBO does light up with passive lighting. Oddly enough, so long as the PSU is plugged into the wall and the ATX 24-pin is connected, the MOBO lights are on whether or not the PSU is I or O. Went high with the PSU wattage to prep for upgrades with another GPU if needed.

Have been running through the troubleshooting checklist as well as this vid . Testing everything outside the case and still no luck - issue is that currently we don't have other components to check with.

CPU = AMD Ryzen 7 5800X
FAN = Noctua NH-U12S
MOBO = ASUS ROG Crosshair VIII Extreme
RAM = G.Skill Trident Z NEO Series 128GB (4 x 32GB) DDR4 3600
GPU = MSI NVIDIA GeForce RTX 3060 Ti
STORAGE = 2x WD SATA SSD M.2 2280
POWER = be quiet! Dark Power Pro 12 1500W
CASE = phanteks enthoo pro full tower
Est wattage 925

I find the "off" PSU still lighting the MOBO real strange - I also have an ASUS MOBO and a 1500W power supply which... when set to "off" kills all lights and everything in the case.

 

[narchon45]

Can also confirm that no QLEDs are coming on and that the BIOS flashback continues to fail (this may just be because the installed version is the same as the latest - only saw a single version listed here. )

 

[Vic 40]

only saw a single version listed here. )

Your link gives different motherboard, this is the one that is mentioned in your first post,
https://rog.asus.com/motherboards/rog-crosshair/rog-crosshair-viii-extreme-model/helpdesk_bios

CPU = AMD Ryzen 7 5800X
FAN = Noctua NH-U12S
MOBO = ASUS ROG Crosshair VIII Extreme
RAM = G.Skill Trident Z NEO Series 128GB (4 x 32GB) DDR4 3600
GPU = MSI NVIDIA GeForce RTX 3060 Ti
STORAGE = 2x WD SATA SSD M.2 2280
POWER = be quiet! Dark Power Pro 12 1500W
CASE = phanteks enthoo pro full tower
Est wattage 925

"Red" never with those components, not even likely with a RX 3090.

 

[jonnyguru]

It's not. If the PSU is on and not powering anything, the bulk cap is still fully charged and will take a long time to discharge if all it is doing is lighting an LED.

 

[narchon45]

Thanks for the responses all - guess I severely overestimated, the Newegg wattage calculator gives me like 500W. Is there a detriment to having a PSU that is far beyond the required amount?

Makes sense about the power discharge, was comparing to my full PC that goes dark after a few seconds.... They were supposed to have a PC shop technician come around and investigate yesterday but he ghosted lol. I'll update when there's any additional info.

 

[Vic 40]

Do look at that link i gave for the right motherboard and see if that latest bios is newer.

Too much power btw is not going to hurt, but under light loads or just idle you're efficiency might be underwhelming.

 

[narchon45]

Do look at that link i gave for the right motherboard and see if that latest bios is newer.

Too much power btw is not going to hurt, but under light loads or just idle you're efficiency might be underwhelming.

Ah sorry I didn't mention above. I did use the DL from that page, but just manually had them rename to 'C8E.CAP' given that the rename tool (.exe) doesn't work on their Macs LOL. Appreciate you checking back in. Guess we'll be waiting for some post-Thanksgiving resolution, have a good one!

 

[emitfudd]

I'm pretty sure there are BIOS settings that keep the RGB lights on even when the machine is powered down and I think it is the default based on my recent build.

Edit: After thinking about this more, they shouldn't stay on with the PSU turned off. What Jonnyguru said about the capacitors makes the most sense.

 

[Vic 40]

Guess we'll be waiting for some post-Thanksgiving resolution, have a good one!

Okay, you too.🙂