Question Wanted to add a GPU, GTX 760, to pre-build HP Compaq 8200 elite, NEED HELP 👏🏼

[jure sotosek]

So I wanted to add a GPU to my prebuild computer so I could game. The computer I have is something similar to this. The graphics card a bought is this, MSI GTX 760.

I knew the PSU in the computer won't cut it so I also bought a Corsair RM 650X PSU, something like this. Then I figured out that the connectors on the PSU and the motherboard are not compatible and I decided to use the new PSU I bought to power only the GPU and "short" it so it would be turned on.

So I plugged everything in and tried to boot the computer with just the new GPU inside, it not being connected to the new PSU. The computer wouldn't boot.

Then I plugged just one 8 pin power cable into the GPU and it would spin up and the computer would boot but the NVIDIA driver didn't want to install since it could not detect the card and also the online tool NVIDIA provides for detecting which GPU you have returned nothing.

This is where it gets weird. The GPU has two connectors, one 8-pin, and one 6-pin. The computer only boots if only ONE is plugged, the second you plug the second one in it just crashes and refuses to boot. No matter which one is plugged first, here is a video:

View: https://www.youtube.com/watch?v=GkzfZ0fktVs&feature=youtu.be


Here is a photo of how I "shorted" the GPU:

https://imgur.com/1dpmrzn

View: https://imgur.com/1dpmrzn


And the slot I'm using:

https://imgur.com/mYoAho2

View: https://imgur.com/mYoAho2



Do you guys have ANY idea on how to fix this, because I don't 😓

 

[Zephyl]

If possible, get a new motherboard. OEM motherboards are often very... unique. It could even be that the motherboard doesn't supply the standard 75W on the x16 slot. It should be pretty easy to find an LGA1155 motherboard used and working, maybe even new. That is, if the case supports a standard microATX form factor, which appears to be the case. You would need to install Windows over again if you did this.

 

[crystalcity]

I'm pretty sure I've setup one or two of those boxes with low TDP graphics cards and they worked fine. gtx750 and 1050.

This probably will help you out just as little as the previous comment, but.. get a 1050ti. Other wise buy a cheap used dell with standard power connector and sell that box.

What you have done should work fine, but who knows why it wont.

Another thing you could try is buy one of the PSU adapter cables, but you need to be careful with those because a lot times they will say they work with ten different models of OEM computer, when in reality you have to swap some pins around for 5 of the 10 models. The adapters are 10 to $20.

 

[crystalcity]

Your GPU eats power BOTH through the slot and the power connectors. I'm no electrician, but you could have ground issues, or flow issues with 2 different 12v supply voltage levels. If your case PSU is 12.35v and your external PSU is 12.10v would the case PSU try to flow power through your GPU into the external PSU? Maybe somebody more familiar with GPU's and multiple PSU's can add their thoughts here.

Its a simpler story when you have 2 PSU's supplying totally separate devices, but here you have two PSU's both feeding in to the same device. Personally I wouldn't try this in carpeted room if you catch my drift.