Thanks for reply.
Mouse/keyboard ok on other pc
Removed all usb`s
Cleared cmos via button on mobo next to internal powerbutton on the mobo
Switched ram-modules.
Checked the original psu, by trying to offline jump-start it via shorting green and black wire
with paperclip. Attached a small fan for load.
Psu did NOT start the fan !!!
Tried exactly same procedure on new psu, and fan starts spinning ok !
Sp I guess original psu is faulty, and has maybe also damaged mobo or cpu.
Original psu is Seasonic x650 watts
To the mobo is installed i7 990x cpu and several hdds.
2 sticks of ram, each 8 gb kingston.
Big question now is : Which unit should I start to replace first ? cpu og mobo ?
(guess replacing cpu firs tis the most easy path, but maybe buying new cpu is a waste of money
if the mobo is the culprit ?)
Any advise highly appreciated.