No signal on monitor

Hello, I've been having this problem lately. I power on my computer everything's working but the monitor says no signal. I tried to boot the computer without the gpu in it and it worked. Then I had my uncle replace it and it seemed to work. But now today I moved my computer. Was gona bring it to a friend but after packing it I changed my mind and put it back on the table resulting in making it say No signal. Could be a cable that's damaged or something? Please help!