Hifonics Maxximus X4 protect

Working on a Hifonics Maxximus X4 2 channel class D, two boards in one housing. When switching on, it goes directly in protect, with very low inrush current.
When I quick "pulse" the remote of the power supply for about one minute , I got about +/-30V rail voltage. Inrush current about 1A. Power on and protect led is flashing.
Mosfets both boards PS and amplifier are OK.

I sustpect the protection itself, but I'm not familiar with the boards used.. some pics of the boards and PS driverboard. If there are schematics available for this amp or similar ones, that would be a great help for me.

hifonics_maxximus_x4_0.jpg hifonics_maxximus_x4_0a.jpg hifonics_maxximus_x4_1.jpg hifonics_maxximus_x4_2.jpg hifonics_maxximus_x4_3.jpg hifonics_maxximus_x4_4.jpg hifonics_maxximus_x4_5.jpg .