2014 27 inch Imac. No display or output. All diagnostic leds lit up

[gersrt]

Hi. I'm trying to figure out what the issue is with my imac 2014 27 retina. When I turn on the screen goes light black and no chime. There is no output from the back port to hdmi.


I thought at first it might be a gpu issue. But all four diagnostic leds are lit up inside. Was sure if there was an issue with the gpu one of them would be off.


Any help please?