RouterBoard 951G can't ping but no access

I’ve tried to configure a RouterBoard 951G then, shut it down by remove power (is there another way to safely turn it down?), next I’ve turn it on, it ping, but no access to web interface and telnet.
I’ve tried many times, after reset to factory settings it is accessible, then I reconfigure it and keep turning back.

What I’ve tried is STATIC IP ADDRESS_ 192.168.88.1
Connect to existing SSID
it connects, I see the traffic in the graph then it stop, but keep pinging.

Why happen this?