GTX 960 not displaying *kinda

[xChewbaccax]

This is my first ever post, but I can not find anything to help with my problem. Basically I’m fixing (trying to) a friends PC and I’m getting very weird reactions from the GPU. The gpu will not display anything when all set up normally, but if I follow a very weird sequence of operations it will work fine until I turn the pc off. 
 

M/B is a dell proprietary one I took from a prebuilt I had laying around. 
cpu i5 - 4460

16gb of ddr3 ram

evga gtx 960 (the problem?)

seasonic power supply

 

So the sequence I have to follow to get the gpu to display like normal is as follows:

1) unplug 8 pin from gpu
2) turn on pc for 10secs with no power cable in gpu
3) kill power on back of power supply with switch. 
4) plug 8 pin into gpu
5) turn pc on and poof it works all of a sudden. 

I’m trying to fix this before modding his case to fit a R9 390 I’ve got laying around. 
 

any help is appreciated!

[Applefreak]

17 minutes ago, xChewbaccax said:

This is my first ever post, but I can not find anything to help with my problem. Basically I’m fixing (trying to) a friends PC and I’m getting very weird reactions from the GPU. The gpu will not display anything when all set up normally, but if I follow a very weird sequence of operations it will work fine until I turn the pc off. 
 

M/B is a dell proprietary one I took from a prebuilt I had laying around. 
cpu i5 - 4460

16gb of ddr3 ram

evga gtx 960 (the problem?)

seasonic power supply

 

So the sequence I have to follow to get the gpu to display like normal is as follows:

1) unplug 8 pin from gpu
2) turn on pc for 10secs with no power cable in gpu
3) kill power on back of power supply with switch. 
4) plug 8 pin into gpu
5) turn pc on and poof it works all of a sudden. 

I’m trying to fix this before modding his case to fit a R9 390 I’ve got laying around. 
 

any help is appreciated!

Have you tried a different power supply? Sounds like an issue on the 12V Rail for the graphics card.

[xChewbaccax]

17 minutes ago, Applefreak said:

Have you tried a different power supply? Sounds like an issue on the 12V Rail for the graphics card.

Yes I’ve tried my personal rx 5700 with the 8pin and an gtx 1050 with no pins and they both worked fine every time. I’ve also put the 960 in my pc and it worked perfectly every time. 

[xChewbaccax]

A video of the process and problem. 

[Applefreak]

Try another 8 Pin connector if you have one. Also try running it only on 6 Pin, I have the same card, it does not need the 8 Pin connector. You can try to bypass the PSU with a molex to 6 Pin adapter if you have one. 

That's if it is a card power issue, if not, you may have a bad card. One other thing you can try, the SSC cards have a switch to the select the mode you want the card to run at, try moving it into the other position.

[xChewbaccax]

22 minutes ago, Applefreak said:

Try another 8 Pin connector if you have one. Also try running it only on 6 Pin, I have the same card, it does not need the 8 Pin connector. You can try to bypass the PSU with a molex to 6 Pin adapter if you have one. 

That's if it is a card power issue, if not, you may have a bad card. One other thing you can try, the SSC cards have a switch to the select the mode you want the card to run at, try moving it into the other position.

I just tried the SSC switch (didn’t know about that) but it didn’t change anything. The other cables I’d have to order. I’ve got other power supply cables but nothing to fit this power supply. I’m gonna order the cables and see if that’s the problem. Thank you for the help!