If it's DHCP mode the IP you use will not work.
You can try to scan your IP using
angry IP scanner if you don't know how to do it follow this guide below
Source:
How to use Angry IP Scanner – Beginners Guideand then use this ip range 192.168.0.1 to 192.168.0.256 or this IP range 192.168.1.1 to 192.168.1.256
If you can't find the IP maybe your miner is brick or your SD card is broken try to install a new SD card and flash it with firmware you can find the firmware from here
https://bitcointalk.org/index.php?topic=1257327.0