Hi there!
After a little search in the forum,I decided to create this thread.
The back-light of my beloved N9 is almost dead, and I don't know why.
It works, but just for a second nd, then,it stop, and after is impossible to turn it on again.
Could You give me a solution?
Thank You!!!!

what you mean dead? you not see NOKIA logo while phone booting?

Some more details can help forum's expert to help you.

I don't think N9 has a backlight, as it has OLED display.

It's not backlights fault as N9 has AMOLED display with no backlight. I'm guessing it's a software problem. Probably reflash will fix it.

Sorry to everybody!!
It's just because of my poor english....
Anyway, I didn't mean a backlight in the main screen....i was talking about the camera light, flash and light...
Really sorry about that!
The light o the camera doesn not work : if I use a "torch" app like phonetorch, light goes on for a millisecond and then....nothing....

Does it work from camera video mode?

Well, did this happen after installing some application or tweak?
(when did you first notice it did not work any longer?)

Do you get anything relevant to syslog?

Have you tried anything that could help, uninstalling software or reflashing for example?

I think it started after some "app" installation ,so maybe it's not an hardware problem...
Do You think I'll need to re flash?
(ps : waiting to receive my Jolla in a few months...)

If you know what app caused it, maybe you could try to remove it and see if that helps.

If it is a SW problem, reflashing always helps, as it will bring the device back to clean state.
However, you need to take all backups before it, and also write up what applications you have installed, to reinstall them back after flashing.
Backup procedure will save your application data but not the applications, so you need to reinstall applications separately after the flashing.