senao NOC 3220 complications

Hi there, i've recently been having problems with a few NOC 3220 units. After a day of using them, they stopped broadcasting and couldnt be detected through wireless.

I've checked the components inside and they seem to be alright since the area tends to be covered with frequent lightning storms. While fixing one of the access points, i couldnt get into its administration. I tried many different ips and even the wireless. Although i cant remember its ip right now and i dont have the COM port cable with me right now.

I'd also like to know, what is the best way to configure the access point so that 50 people can connect to it and use it without losing signal, assuming all the 50 are within a 50 meter radius.

Thank you.