Only boot with 1 stick of RAM in slot 4 ,lead to CPU failure (typical for unsuccessful delidding).
Do you have any spare RAM,this one you have is ELPIDA IC chips .
So,both sticks can boot only in slot 4? (of course one by one)
Disconnect all HD (SSD),video card,CD/DVD writer,sound output,USB drivers and keep connected only memory, keyboard and mouse.
Video output take from board itself on back panel.
What is your PSU model,all connection is OK?