hello, i have the same case, its a 7906G, in the back says CP-7906G-V04, this happened after a power failure so we assume thats the problem.
In my case, first the LEDs start to blink, and the appers the Cisco/Java Screen and in the bottom left corner appears a checkbox, and after 10-15 seconds its restarst, you have the same problem??
greetings