No signal detected BenQ/Cant enter BIOS black screen

Aug 15, 2018
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Hello, I've just bought a PC from a friend, the specs are:
i5 3330
GTX 1050
10gb RAM
550w 1tb hdd
So, i tried to turn it on, and it says 'No Signal Detected'. Okay, I removed the graphics card because the cables are all good, i removed the RAM, got it working but just for the moment. Now I have another problem;the PC is starting normally, and then when i get pass "ASUS f2 or del boot blabla" screen, i get a black screen and my keyboard is not working. SO when I restart my PC, I hit F2/del quickly to enter BIOS, but nothing helps. I cant get into the BIOS and everything seems to be working. I even restarted CMOS but now im back to square one, where its saying 'no signal
detected'. I really need help
EDIT: My friend who is a computer scientist says the problem is in the motherboard, but I really dont want to pay for another motherboard if the problem is fixable. I even set a bootable USB with windows but I cant enter BIOS nor can I put the USB because its 'no sig.detec.' again.