GPU not woking in PCI x16 but works in PCI x4

[mkulecondra]

I got my MSI B350m -Mortar with Ryzen 3 1200 and 8GB RAM with Gainward GTX 1050.
My gpu stopped working in pci x16 but works just fine in pci x4 but i get less power then from the pci x16
Gpu works just fine in another pc in pci x16 i tried to use my rx470 in the B350m in the pci x16 but it didnt work as well so i send it to servis but they said that the pci x16 works just fine
So Im asking for help

 

[ffg7]

it is a motherboard issue as 2 different cards have same issue on your board but work on other motherboards. so 2 options is to live with using pci x4 slot or get a new motherboard. how old is the motherboard? can you post a picture of that motherboard to see if any domed or leaking capacitors?