If I may add to the excellent advice already given by Russ:

It is worth also power cycling your Router (which serves the DHCP) at the same time as you power cycle the switch. The unmanaged switch should handle the local traffic between devices, however my experience is that after such troubles, routers often get in a confused state / run slowly until power cycled.

This way you know that you are starting from a clean base state.

John

808v6, M60, MC200, HD621, Lumagen XE, 504, SB Touch, 563, 201, 204, 208, MPMAX 221, M80, Explorer, Explorer2.