Question gpu

sorry, but could you be a bit more detailed?

which hardware are you using?
motherboard, GPU, PSU, monitor

try a different video cable
different monitor/TV
is the video cable connected to the GPU and not the motherboard?
 
It shows a black screen, I tried to change the BIOS, but it still doesn't work. I have a GTX 1070, but it reads a low-end video card, for example a GT 440.