When i connect (hp elite desk) desktop CPU to power socket & when i switch on the power cable button the CPU power on button immediately starts to glow without blinking & it continues like that for unlimited time until i switch on the power cable button. If i long press the power button of CPU it wont make any changes & CPU remains on. But nothing is shown on Display/screen. I tried to troubleshoot by removing all cables including power cable & press hold the power button for more than 15sec but no use. Changed RAM but no change in status.please help me out of situation