I have a prebuilt computer, an Acer aspire gx 281 with a 1070 an ryzen 5 1600. Recently i bought a liquid cooler and my plan was to replace the cpu fan in my case with that one, however my case has no opening on the back, so for me to place the backplate on the backside of the motherboard I need to screw it of completely. Right now I have disconnected everything and removed cooler, case fans and grapicscard etc. and unscrewed all the screws that attached the motherboard to the case. For some reason it’s still stick in place and I have no idea why, Is there something else holding the motherboard down?. somebody pls help!