[Solved] NVIDIA Graphics Card works in x16 slot, AMD Card doesn't.

[moosefuel]

No end to the troubles I've had with my build!

I have a very nice NVIDIA EN210 low power graphics card which I got for my build, originally planning to use the machine as mainly a fileserver. One thing led to another and I got an AMD 7870 for really cheap, and it's incredibly more powerful than my NVIDIA card.

The only problem is, I took my NVIDIA card out of the x16 graphics slot (which is slot #2 on my Dell motherboard), and put the AMD into the exact same slot, and it won't run. The computer powers up, the fans all spin on the case, CPU and card, the monitor wakes from sleep, then tells me "no signal". I would have thought the card was bad except that if I put the card into the #1 slot, everything functions really well (all screens load, from BIOS to macOS), the only problem being that it is an x4 slot so I'm not getting the full performance from the card that I would like. I tried making sure the card is properly seated in slot #2, made sure there was no oxidization on the contacts. I checked the BIOS and tried setting it to the #2 slot for the graphics card, then I tried the "auto" select setting for the card. Nothing will make it work in slot #2 (which is the dedicated graphics card slot). Not even the BIOS will load. If I take it out and put the NVIDIA card back in the same slot, everything is just fine. If I put the AMD card in slot #1 (the slow slot) everything runs just fine.

I should also mention that if I put the AMD card in the #2/Graphics/x16/fast slot and the NVIDIA in another slot, I am able to boot to the BIOS through the NVIDIA card and see that it lists slot #2 as "empty", even though the AMD card is in there.

Has anyone got some insight? I'm using a DELL t3600 board unfortunately as I wanted to make use of cheap available components, so perhaps it's a compatibility issue. The board actually has two x16 slots, but one of them is confined by the case and would only fit a narrow card so I can't try it at the moment.

Can someone see what I'm not getting here?

Much appreciated.

 

[kiiroaka]

I wanted to move the graphics card from my G5 to my Pro 1,1. (I had originally installed the Pro 1,1's GeForce 7300 GT card into the G5, upgraded from the GeForce 6600LE, and the Pro 1,1 I bought didn't have a video card.) I made sure that the power cord was removed from the Pro and I thought that the other end of the AC cord on the G5 was not connected because there was no mouse, keyboard, display, NIC cable nor speakers connected. The units were not powered up. I removed the card from the G5 and it would not work in the Pro 1,1's PCI-E x16 slot, but it did work in the x8 slot. Because the power cord was in fact still connected on the G5 I ended up blowing up a channel. It is now back in the G5, in the x8 slot because it no longer worked in the G5's x16 slot (original position before the swap), so I decided to buy an Apple ATI 4870 for the Pro 1,1 instead. Meanwhile I have two GeForce 76600LEs that I can't use.

Lesson: Never remove nor install any internal component unless the AC cord is removed.
Lesson I didn't have to learn: if You power up a Mac Pro without a video card connected chances are you're going to blow something on the motherboard.

In your case it may be a simple fix: you may now need two PCIe 6 pin power cables connected on your video card.
http://www.tomshardware.com/forum/367056-33-power-asus-radeon-7870

 

[moosefuel]

Thanks for the info. I do have the two power-connectors hooked up, and the card works in the x4 slot, but since it is a x16 card I assume I can't get the full benefit of it.

It is very possible that I blew sometihing in my bumbling in this build. It's my first time building a PC so I have made some stupid mistakes, like not unplugging the AC when changing RAM. I can't remember if I did the same with the graphics card, I hope not but it is possible.

Could you define what you mean by "channel"? Is it one channel per PCI slot, or are there multiple channels per slot? The reason I ask is because the NVIDIA card still works in the slot, even though it's seemingly dead to the AMD card. Maybe there are some pins which are not active.

Thanks.

 

[moosefuel]

OK Update for posterity. My CPU had a tiny but deep scratch on the underside (that's what I get for buying used XEONs off eBay). After replacing the CPU everything works perfectly. All slots and RAM now is fully functional. I'm amazed that the computer was as functional as it was with a little gouge in the CPU like that.