AP was working before, but at one time suddenly stuck with yellow power LED.
Switch with connected AP even can't see MAC address of this AP, so I understand that problem with booting.
1. From your link: LED 1 Only Solid Amber - Discovery finished via WDS, but not in progress.
(in one port of switch is EWC in other port is AP, they in one VLAN)
2. I can't see MAC address of this AP on switch port.