Hardware PS3 Slim has power, No image, no recovery

[Robika]

Hello there!

I have gotten a ps3 slim SLUS - 3004A from a friend who said he had it in a drawer for a year or so. No it seems not be in working state.
It turns on but it will no display image, via HDMI and can't enter recovery. The fans do seem to work but in a really low mode.
I could start the cleaning mode (turn it on with eject button pressed).
I can't get a PSU to test out if it works is there a way test out if the PSU is fine.

Thanks in advance!