What do the different wireless status light colors and blinking patterns mean on the HP Photosmart 7520?

A solid blue light indicates that a wireless connection has been established and you can print. A slow blinking light means wireless is on but the printer is not connected to a network, so you should make sure the printer is within range of the wireless signal. A fast blinking light indicates a wireless error, and you should refer to the message on the printer display for more information. (Page 2)