Some computers are not connecting to LAN

Hello,

This is my first post in this forum I hope will get some great help from you guys. Here is the situation

I've an internet cafe of 20 computers which are directly connected to an ethernet switch & were working fine till yesterday, Today one of the AC started dripping water on that switch after that some computers stoppped working, I changed that switch I replaced with a new switch, But the problem is still there, let's say port no 4 is working and no 5 is not working when i interchanged the cables port 5 started working and port 4 stopped. This means there is nothing wrong with the cables itself, My question is what other possible reasons could be which is stopping those 10 computers to connect to the LAN?

we have a server based network, We configured the ips manually, so ips are ok,

Thank you in advance