Question Bought a new GPU but it's black screen even though the fans is spinning

Oct 3, 2023
My little brother just bought an ASUS RX 470 graphic card but when we try to turn on the pc after installing it, it shows black screen even though the GPU fans is spinning.

We have uninstalled previous GPU driver but it still the same. We also reinstalled windows, trying to install the new GPU driver (by using onboard graphic) but the driver installer can't detect it. Bios, dxdiag and device manager can't detect it either.

Can anybody please tell us what is wrong here? Is it the GPU that's broken or is it because the motherboard doesn't support the GPU? (we use old motherboard, the cpu can't be removed and the motherboard doesn't support UEFI. Im not very good at computer thing but when I asked my brother he doesn't know what kind of motherboard he have so I can't provide much information on the motherboard.)

One other thing, there is something that can lock the GPU in the slot but the new GPU can't be locked even though I fit it, could that be the reason too? Im sure the power cables is fine and the VGA cable is connected well.

Please help us. And sorry for my english.