PS3 green light but no image

Hello Guys,

My sister sent me my old PS3 Slim from Portugal to Belgium so I could put some games to my kid.
She was playing with it just the week before and everything was working well.
When I tried to turn it on, it does the normal beep and the green light appears, but only after 30 seconds the console really starts to work and the controller connects to it.
The problem is that there is no image in the screen.
I tried with both hdmi and av cables, change the hdmi cables, and nothing works.
I did open it to check the dust, gave it a clean; replaced the thermal paste, and after that it stays the same.

Tried after to format the hdd and add the update to the usb flash drive but there is no image either.

I tried to reset the graphic settings with the "two beeps" but it never does the two beeps.

Tried to turn it on without disk to see if at least would give the error and nothing too.

Anyone knows a way that could fix it?