Connectivity Issues with ICX-7150-C12

[kqnguyen1]

Having connectivity issues with my ICX-7150 and APs (Lennar home). Connection is very spotty and slow (keeps dropping randomly). Have been reading through the forum for similar issues and seems it could be caused by a routing issue that could occur after a power outage. Already attempted to reset the switch and also unplug/reconnect. 

Websites not loading
Devices getting disconnected randomly
Devices often not being able to connect to internet

Tried to access the switch via the web browser but no username/PW combinations seem to work. Need some help on next steps to find correct switch IP address, log in, etc., please advise thank you.