Question Upgraded GPU and PSU and can't get system to boot

[ecraven411]

Last year during peak pandemic I finally just bought a prebuilt system since it was impossible to get a graphics card. A year later I finally got a hit on the EVGA queue I was in for a 3080, so decided I would just grab it and give the old one to a friend. The prebuilt had a pretty questionable PSU, so I also grabbed a Corsair RM 850x gold certified to have around for the 3080 and hopefully be future-proof enough for another build down the road.

Both came today and I set out removing the 3060, and unplugging all the power connectors. Only thing that worried me was how much of a mess all of the case cords were. There was no way I was going to be able to reassemble them in the manner they were set up in the prebuilt, but I wasn't too concerned as I wanted to plug the case fans into the motherboard anyway (they had all been direct PSU connections before). I didn't touch the front panel connection to the motherboard (called the "JSP1" slot on this MSI board), and reconnected the motherboard, cpu, three 8-pin PCIs on the GPU, and harddrive to the new PSU. Only part that worried me was how hard the original 24 pin motherboard connection was to get out. Required a lot more force than I would've liked.

Went to boot, and got absolutely nothing. Unplugged the PSU from everything and tried the paper clip trick to check if it was DOA. got a quiet click and half a second of fan movement which is supposed to be normal for the Corsair PSU's that have zero fan mode under no load. Then I reconnected everything and unplugged the JSP1 connection on the motherboard and tried jump starting it by touching the two top right pins. Got nothing there. Leads me to believe it's a motherboard problem, but other then it being completely dead from something I did during the process, I don't know what might be wrong. Pretty gutted about the whole thing if that's the case. I thought I was capable of this pretty basic upgrade, and I'm way less confident if I have to go and try and reseat the CPU and everything if I did break the motherboard. Any other troubleshooting I can try on the motherboard?

 

[boju]

Was all power related cables, if modular from old psu; cpu, sata, pcie, anything that connects to psu itself replaced with Corsair's own cables?

 

[ecraven411]

Old PSU was not modular. All cables are from the new PSU.

 

[boju]

What other parts does the system consist of?

 

[ecraven411]

i9-10850k
EVGA GTX 3080
MSI Z590 Pro
16GB Ballistix DDR4 RAM
Corsair 850rx

Going to try plugging the old PSU back in and seeing If I get a boot. That would at least determine if it was the 24 pin on the new cable that wasnt working I guess?

 

[boju]

First can you remove gpu and try igpu from motherboard?

 

[ecraven411]

I can try that. Wouldn't the motherboard still boot to bios even if the gpu wasn't working though?

 

[boju]

No because gpu still needs to display something and igpu is disabled with gpu installed.

*You are connecting display cable to 3080 yeah, not the mobo video ports?

 

[ecraven411]

Ya I'm connected to the GPU display port, but when I say doesn't turn on I mean like the thing is a brick. The psu fan doesn't even turn on, hard drive doesn't make a sound, etc.

 

[boju]

Check motherboard manual online and see page about case power button and make sure that is still connected and to the correct pins.

 

[ecraven411]

Ya I never disconnected any of the pins connected to the case

 

[boju]

Check it's still connected properly in case it was lifted unknowingly. Check psu end of cables are connected properly. Try without gpu to check if system still remains dark. If nothing changes then i guess trying your psu idea is next.

Wouldn't be anything wrong with cpu. Something to do with psu, gpu, or possibly motherboard's 24pin relating to recent changes.

 

[ecraven411]

Just reconnected the power pins and nothing. Trying the old psu without GPU. Just confirm, the front panel draws its power from the motherboard? It doesn't need its own psu connection.

 

[ecraven411]

Ya just tried the connecting the old psu. just plugged in the motherboard and cpu with no gpu. No life whatsoever. I'm actually devastated. Never touching a fricking motherboard again.

 

[boju]

Just confirm, the front panel draws its power from the motherboard?

It's just a switch that tells the motherboard to turn on, it doesn't require independent power. The power comes from 24pin.

Id hate to blame the 24pin plug on motherboard but looks like it.

 

[ecraven411]

Appreciate the help. I knew the original psu that came with the pc was a piece of crap, and the 24 pin connector was not smooth to remove like the corsair one. Probably damaged a pin on the way out. That's the risk of buying pre-built I guess. My concern is I have no confidence in replacing the whole motherboard

 

[boju]

Sorry for delay i started work.

There's not all that much to it. Motherboard held down by 9 screws. Some isopropyl to clean off old paste from cpu. See how cpu is oriented and locked in socket by leaver and do same with new motherboard. And same with cooler. Manual will explain which pins are for case buttons etc and just follow suit.

Get some noctua nh1 thermal paste if need more. See application videos best way to apply paste for your cpu.

 

[boju]

Silly question you did switch on the psu right 😛?

 

[ecraven411]

Yes PSU switched on and off multiple times. Theoretically I know how to install everything on a new motherboard. Theoretically I also knew how to do a simple PSU and GPU replacement as well lol.

 

[boju]

Think you were unlucky with a stubborn 24pin connector that just didn't want to let go. Should have mentioned that earlier. You won't have any more troubles.