Hello all,

I've been using my N900 for 4 mounts without any problem, but today all of a sudden my phone is closed itself while it had more than %50 of battery -that's why i think first-,
for one day i was trying to charge and trying to open again and again, without getting any result. Now I've fully charged the battery and noticed that keyboard back lights are working properly, /when i open the phone, when the white light fades keyboard lids and then works as it should, when i lock the device, it turns of/

Ok, with shorter words;

my screen went black and I can't see anything whatever i try, I'm fully charged and as far as i could understand device opens properly but i'm not so sure of that.

any suggestion before i go to the technical support?

have you tried plugging in the tv out to see if that is working?

I am going to try that,

but will I be able to even see the screen that we enter device lock password?

urm i think the tv out signal kicks in before the nokia hands? if not just type your password and press enter?

I've connected my phone to tv and I've tried to type my password and press enter, either way (i was successful or not) All i could see was a grey screen. It was black at the begginning and it turned into grey when phone had open.

Sounds like perhaps you've run into this bug:
https://bugs.maemo.org/show_bug.cgi?id=9150

If you have sshd installed, see if you can ssh into it and check the dmesg.