Question Is my GPU dead on arrival?

[Syabatron]

I just upgraded from a 6600xt to a Zotac 4080 Super Amp and spent 6 hours yesterday installing the card, the new PSU, and some new RAM. The part swap was easy but I spent the majority of the time trying to get it to POST. The final thing I tried was to just switch my GPU back to the 6600xt and it POST'd immediately, making me think that my 4080 Super might be dead on arrival. The debug LED lights on the mobo would either stay on BOOT and VGA or there wouldn't be any lights at all, but still no display. The mobo is an ASRock B550m Pro4. My PSU is the most recent version of the Corsair RM850x.

Troubleshooting steps I have tried:

* Reseating 4080 Super
* Reseating RAM
* Swapping new RAM out for my known-good old RAM
* Trying different output ports on the 4080 Super, including trying both DP and HDMI
* Trying different monitors on the 4080 Super
* On the 4080 Super reseating the dedicated 12V-2x6 cable that came with the PSU
* Pushing on all of the PSU connections to verify they aren't loose
* Disconnecting all devices aside from the keyboard and one monitor
* Shorting the 2 CMOS pins with a screwdriver
* Removing CMOS battery, clearing power with power button, and letting it sit for 10 mins before putting the battery back in

Basically I've tried all of the steps I could think of. After swapping back to the 6600xt I was able to POST on first try, boot into my USB and install Windows 11 on my new SSD. I also have the new RAM in, so it looks like thats not the issue. The only other thing I can think of for the 4080 Super is to try using the adapter cable it comes with instead of the dedicated 12V cable from the PSU. I also saw some people with similar problems saying they let the PC sit on POSTing for 30 mins and it eventually POST'd so maybe I'll try that?

Are there any steps I've missed, or is it pretty much a lost cause at this point?

 

[COLGeek]

What is the make/model of your PSU?

 

[SkyNetRising]

Are there any steps I've missed, or is it pretty much a lost cause at this point?

Try
disabling Secure Boot,
placing graphics card into second PCIE x16 slot.

 

[Syabatron]

What is the make/model of your PSU?

This version of the Corsair RM850x: https://www.corsair.com/us/en/p/psu...850x-fully-modular-power-supply-cp-9020270-na

 

[Syabatron]

Try
disabling Secure Boot,
placing graphics card into second PCIE x16 slot.

Secure Boot was disabled when I was trying the 4080 Super, I didn't enable it until I was able to POST with the 6600xt and install Windows 11.

Unfortunately my case doesn't have room for me to put the GPU into the second PCIE x16 slot

 

[COLGeek]

Those adapter cables can be problematic. Rather than using that (to attach to a couple PCIe connectors), you should get the 12VHPWR cable needed to connect directly to your PSU instead of using the adapter cable.

This could be the issue.

https://www.corsair.com/us/en/p/pc-...-5-12v-2x6-600w-cable-type-4-black-cp-8920331

 

[Syabatron]

Those adapter cables can be problematic. Rather than using that (to attach to a couple PCIe connectors), you should get the 12VHPWR cable needed to connect directly to your PSU instead of using the adapter cable.

This could be the issue.

The PSU comes with a dedicated 12V-2x6 cable (Corsairs replacement for the 12VHPWR) that I've been using, it's not an adapter. I was just thinking about using the adapter that came with the GPU instead just to see if that would help

This is the 12V-2x6 cable: https://assets.corsair.com/image/up...-config/gallery/black/850/RM850x_2024_04.webp

It's the same connector on both PSU and GPU ends

 

[COLGeek]

The PSU comes with a dedicated 12V-2x6 cable (Corsairs replacement for the 12VHPWR) that I've been using, it's not an adapter. I was just thinking about using the adapter that came with the GPU instead just to see if that would help

I see. Good to know.

Do you have access to another PC to test the GPU in?

 

[Syabatron]

I see. Good to know.

Do you have access to another PC to test the GPU in?

I don't at home but I might be able to see if a friend would be down to let me try it in his PC

 

[COLGeek]

That would help isolate the problem.

 

[SkyNetRising]

Unfortunately my case doesn't have room for me to put the GPU into the second PCIE x16 slot

You can remove motherboard from pc case and test it that way or
use a PCIE riser cable.

 

[Syabatron]

That would help isolate the problem.

You can remove motherboard from pc case and test it that way or
use a PCIE riser cable.

I'm not sure how to mention/@ you guys on here, so I just replied to these comments because I wanted to let you guys know that I figured out the issue. It was a problem with Corsair's 12V-2x6 cable. I'm not sure why, but it simply just was not working. I decided to try out the adapter that came with the GPU and plug in the 3 PCIe 6+2pin connectors needed to the 12VHPWR adapter, and it POST'd and is working now!

I knew there are a ton of issues with 12VHPWR and with the adapters, which is why I bought this PSU in the first place because it has a dedicated 12VHPWR/12V-2x6 cable. It's just funny that is what screwed me over lol

Anyways, I appreciate the help, thank you so much! Have a happy New Year!

 

[COLGeek]

Make 100% sure that you have the connections firmly attached. Very firmly.

 

[Syabatron]

Make 100% sure that you have the connections firmly attached. Very firmly.

I pushed on each connection as hard as I realistically could at least 3 times so I hope it'll be okay. I know about the dangers of 12VHPWR so I was extra cautious

 

[COLGeek]

Have fun with the new config. Happy New Year!