Today I found and old W910i. It looked to be in relatively good condition. Only the plastics were dirty and sticky as some old plastics are.
As it had no battery, I just soldered some LiPol to the pins and tried to turn it on. It started to boot, the buttons started to glow, the boot tone sounded, but the screen is still black. I can move through menus by arrow keys and can hear the sound meaning the moves in menu, and also I have managed to play some sound from media player. However, the screen is still dead.
Maybe I will try to order a replacement screen, which surprisingly costs around 4EUR, or maybe I will give it to a friend to just put it on the shelf, because I am not sure if the problem is in the screen, which looks good, or if it is somewhere deeper.

Jan "Jenkings" Škoda - blog
Simplifying IT, Amplifying Knowledge