Remove the add-in controller and try to boot the server with minimal configuration (one CPU, one DIMM). If the server can boot, add the components one at a time. If it doesn't boot, check the POST Code LEDs on the back of the board. See Appendix E of the board Technical product specification for more details about POST Code LEDs.
Thanks for your answer.
I tired also with Minimum configuration,
I tried without any Controller Card, only the Board, changed CPUs, changed RAM anf the CASE with Power Supplies,., nothing helps.
All other components work, have here more S5520HC/SC Servers.
I cannot Check the Post Code LEDs, the System doesn't power on.
Have only System Status LED solid amber light & ID LED solid blue light!
Motherboard will be exchanged (warranty)