PS4 WLOD Got signal but nothing shows up (black screen)

Hello there!

So i got this PS4 pre-owned, it starts with the usual beep and pulsing blue light. After a few seconds the light turns white and stays white constant. The information i got from previous owner is that the hdmi port was replaced due to this same problem (black screen) but when replacement didnt fix the problem the ps4 got put to storage.

When i turn on the PS4 my monitor wakes up, so there is a signal. However there is nothing shown on screen, just all black. And a constant white light on the ps4.

Booting into safe mode is a no-go screen is still black but with signal.

hdmi-cables have been switched around, and confirmed working on other devices, there is no reciver in the middle just PS4 <-> Monitor

Even tried removing hdd to se if the ps4 would throw me an error but same problem, black screen. I also connected the harddrive to my PC, checked all partitions in dskmgr and they are all empty, they are there all 15 of them but they are shown as empty (100% free space) might just be that windows cant recongnize the filesystem.

I’ve been at this for a couple of hours now all search results on google and youtube hasnt helpt me.

Any thoughts or suggestions ?

Lilja