The seller send me a new one and now everythink works fine :-)

If I disconnect the molex power supply to the Riser I still have the problem and the fans on the second gpu in the riser stop spinning, of course.

But I think my problem isn´t the driver of the GPU because I already have it and I don´t even get a signal of my first GPU when I have connected the Riser without/with a gpu. As soon as I have connected my pci riser I only get a signal out of my onboard gpu, but the fans of my gpus are spinning.

I am using the Asus B85M-E motherboard.

Yes I have the latest version of my BIOS.
Which Amd driver should I install?

Is there maybe a criterion for which I have to look for when I want to buy myself a new mainboard or is there a list of the mainboards supporting the PCI riser? :-)

It´s a PCI-E 1x to pcie 16x riser, the one you can the in the second image. The power supply is molex already tried it with a different power supply.
Here´s the url where I bought the Riser:

https://de.aliexpress.com/item/60CM-PCI-Express-PCI-E-1X-to-16X-Riser-Card-Adapter-PCIE-Extender-with-USB-3/32766163943.html?spm=2114.010208.3.45.OKRXPJ&ws_ab_test=searchweb0_0,searchweb201602_1_10065_10068_10501_10503_10000032_119_10000025_10000029_430_10000028_10060_10062_10056_10055_10000062_10054_10059_10099_10000022_10000012_10103_10000015_10102_10101_10096_10000018_10000019_10000056_10000059_10052_10053_10107_10050_10106_10051_10000053_10000007_10000050_10084_10083_10118_10000047_10080_10082_10081_10110_10111_10112_10113_10114_10115_10000041_10000044_10078_10079_10000038_429_10073_10000035_10121-10052_10503_10501,searchweb201603_10,afswitch_3,single_sort_3_default&btsid=9a0b679e-02b9-49ff-97db-40fcb3688449

Yes I defenetly have enough power I already conncected the PCI riser to a spererate power supply.
My first GPU is a AMD Radeon R7 370 my second one is a Nvidia Quadro FX 3800 I already tryed it with a Nvidia quatro FX 1700
No I don´t use any splitters or adapters.
I restarted my Pc multible times.

http://imgur.com/DU1CqCR
Here a picture of the Device manager. I only have attached the Riser and my first gpu. You can see the setup in this picture:
http://imgur.com/a/4YvtP

I have no special drivers installed for the riser because I thought you don´t need any drivers for the PCI riser, is this right?

I "deactivated" the onbaord ( I can only set the priority) but didn´t helped the power plugin fits correct.
I tried to start my pc with just the riser attached without a gpu in the riser but nothing is better( I don´t get a signal of my main gpu and nothing shows up in the device manager :-( )

Yes I get video from 1 GPU without the riser. When I instert the second GPU directly on the mainboard both GPUs work.
My GPUs aren´t modded should I do this?
I get a signal of the onboard GPU when I attach the riser, but my PC doesn´t even recognize my other GPUs in the device manager, when the riser is connected.

I am using Windows 10 and the fans are spinning on both cards. I don´t get a signal from the graphic cards so it doesnt care to which GPU I connect the hdmi cable or DVI cable.
My first GPU is attached to my motherboard´s pcie x16 slot. I already tried to only connect the pci riser so i disconnected my first GPU and only connected my Pci riser but I had the same problem.
My motherboard has onboard video.

Hi Guys,

I have a problem, because I recently bought a PCI riser/extender card and now I want to attach a second graphic card to my PC. But when I attached the Pci riser card with a graphic card I get a black screen with no signal.

Do you have any solutions?

MrKK11