Hi,
Try pressing the power button - check here (last part of chapter)
http://www.cisco.com/c/en/us/td/docs/app_ntwk_services/waas/wave/installation/574/guide/WAVE-574_HIG/574intr.html#wp1040319
The WAVE-574 (and actually the WAVE-274 model) have a somewhat weird power behaviour.
Even though power is attached to the device, it is not automatically powered on - you have to press the power button.
Otherwise you'll end with this amber ligth.
The NIC link led is lit because it receives link from the switch.
Hope this helps.
Best Regards
Finn