I also have the same problem.
The phone was not wet and didn't fall.
I was using the phone as a GPS and suddenly it started flickering.

When I turn the screen off, it doesn't turn on again.
When I turn on the phone, I sometimes have a flickering image, but most of the time no image at all.
The device works when I use tv-out.

Here is an image of my screen
http://img856.imageshack.us/img856/4127/n900flicker.jpg

Does someone have a fix for this? Or can tell me the cause of this problem?

Thanks in advance.

Further to this thread, I too have had recent problems with my N900 displaying a flickering screen or blank screen exactly as in the picture linked to the last post. This happened for several days on a random basis but with no reoccurrence for the last couple of weeks!

Has anyone managed to find out conclusively what causes this? Although I'm prepared to take my N900 to Nokia It would be useful to know as much as I can as I guess it’s likely it'll just get returned with no defect found!

Thanks in advance

Just for information, the flickering lasted one week.
I haven't had any problem with the phone since august and I use it every day.
Still don't know what was the cause.

No reoccurrence of flickering on my N900 since either!

Very frustrating as it let me down when I needed to use it extensively as a Sat Nav etc. It would certainly be good to know what the cause of this is!

Guys i am having the same problem as state, I was just using my N900 then sudden the flickers at the screen appear. I dont know what to do, this is more than a year old and I dont want to lose this phone. Please help, I need solutions. thanks

Ok, same problem here . If someone knows any way to fix that i'd like to know. Thanks in advance.
Ps: my n900 is 2 years old now.

Same here, started in just one spot, and for now I buy cheap screen protector, but really hate protectors.

Anyway i think there is no solution here, I must make a peace with cheap screen protector

I'm facing that problem since last weekend. Yesterday i made a full reflash but w/o many hopes and like i was figured out, nothing changes. Now i'm pretty sure that its a hardware problem. Today i've got my device opened and nothing seems to be wrong. All flex cables properlly connected and nothing seems to be broken, wet or something like that.
So, what do you guys think about this flickering horizontal lines problem ? How can i try to fix that ? For now, i have 2 choices: either buy a new flex cable http://www.parts4repair.com/nokia-n9...-front-camera/ or buy a new display http://www.ebay.com/itm/New-OEM-Noki...-/120746249398. What do you think that could be a better choice ? I just don't want to waste money That kind of sttuff are pretty expensive here in Brazil.
I really need an expert opinion here ! Thank you very much.

Edit: after buying and install a new LCD, the problem still there. So, i did order a new ribbon and now it works. Just for record, it's sooo easy to change that ribbon. I just recomend that you use the right screwdivers. No place for workarounds here or you will fuc* your screws.
Thanks all.

Since last afternoon, I've had the same flickering problem, which looks like the image posted by darodi. It happens one or two seconds after the initial Nokia screen appears at boot time (so, this really seems to be a hardware problem), then never stops. The lines entirely white are not affected. Changing the battery didn't help.

Can you try connecting to N900 through vnc server? This way you could understand if there is a faulty cable/lcd screen or the problem lies in the gpu.