QSC K12.2 Powered Speaker: Front Panel Flashing. Believed to be in protection.

Hi there and salutes to all.
This is one of the latest model of powered speaker from QSC. I believe it is in protection mode since it won't turn ON, it only flashes the front lights ON/OFF . 
I have no service information or schematics. I open and took a visual inspection and saw nothing in particular, no burn spots. I open the Amp/Power supply module and
checked for burnt diodes or transistors and found none. I wonder if there is a service manuals and schematics available somewhere  that can help troubleshoot and repairs this speaker.
I have the exact same problem with a JBLPRX725: Front panel light flashes ON/OFF, the speaker never turns ON. I open it and checked for obvious defective components and found none. I checked for burnt diodes or burnt output transistors and found none.  I Know for sure the problem is in the input board ( I swapped input boards with second speaker ) JBL told me "just fix it or send it to a service center" ( G's, what a great idea, they are so smart I could never have figured that out all by myself ).
Thanks every one.
Ezio