a buddy bouhgt a used hdo2, we was tuning his quad and when i finished a battery and gave him the goggles back for the next battery the screens was black and there didnt came any sign of life from the screebs seems than.

annoying to see a beginner disappointed by gear fault :

does someone have an idea or a good link for a possible soluition?

im actualy looling for the connection of the displays  and the pdb online, i saw there came some with unattched ribon cables in a yt vid in the past. 
maybe its just pluged out by itself? should i open them and look into that direction?

thanks in advance for any help

Does it show any signs of life at all?
Does it turn on the vrx module?
If it’s showing signs of life but just the screens aren’t working, I’d say open it up and check the ribbon cables.

If it’s not showing *any* signs of life, I’d try using a different battery and a different plug to power it, if still no life, I’d open it up and start probing. If those things have an internal fuse, I’d start there.

the displays got black while vrx and dvr module are still working, only the displays doesnt work.

I’d say go ahead and open them up then.

The hdo and hdo2 share the same shell, so you can follow Oscar’s guide to opening them up:
https://oscarliang.com/open-up-fatshark-goggles-hdo/

i wrote the fatshark customer care, but i will open if i cant progress with their help

on reddit i found a simular description from a new hdo2 backthan where a driver board replacement did solve it.

lets see what fatshark customer care does, i will report back their help