Hi Jim,
Here are my questions and thoughts that follow them.
Do you have a local router serving DHCP? The AP will look for an address
before going with the default IP. If you have one and access to it, look for your
AP MAC address in lease table.
Good to wait for the AP to go full green on the PWR LED before trying to find it.
If you only connect PC/AP to a PoE port for access, have you pre-configured your
PC to a 192.168.0.x (other than .1) IP address; or, does your PC pull an IP from your
network if you connect thru the R300 ethernet Pass-Through or LAN/Uplink ports?