AW2518HF, power cable, buzzing noise

Hello.

About a month ago I have purchased the Dell Alienware AW2518HF Gaming 240Hz monitor.

Recently, I have unplugged my monitor to move it to a different desk and when I plugged it back in, I had problems with it turning on and buzzing noises coming out of the port where the power cable goes in. I was using the power cable that came in the box at the time of the problem. I tried using a different power cable and still the same problem, a buzzing noise whenever the power cable is not put in a good position. Whenever I try to move the monitor, it turns off and the buzzing is there, prompting me to move the cable until it turns on and stops buzzing. Is there any way to fix this?

Thanks.