I had this problem recently. I have 1 year with my N900, 6 days ago the touch screen began to fail. This video shows the same problems I have: http://www.youtube.com/watch?v=3QpNl42RO6c
I open the device and cleaned. I did clean the digitizer and the lcd, checked every ribbon was correctly connected and remove all the dust. Then I closed the device, and power it on with still the same problem. After 10 minutes of touching the screen, it fixed. I am not using any kind of screen protector.
Then it was all wonderful, but 1 day ago the problem returned! This time i wasn't able to fix it. I tried open it and clean it again but no success.
Other things to consider is that i have installed NITDroid. When i power on my N900 with slide up, i have 4 options in Multiboot:
1. Original Kernel
2. Power 48
3. Power 49
4. NITDroid
If i select the original kernel it keeps booting the nokia logo in a loop. If i select the second option, multiboot shows me an error. The third option boots normally with kernel power 49. And the last option boots NITDroid normally too(NITDroid is also affected with the touch screen problem)
Right now i'm able to control the device from my PC via VNC. I've made a backup of all my stuff. The only solution i've think of is buying a new digitizer from eBay.
Is there someone having the same problem as i do? Thank you for help and sorry for my bad english.
thanks for your reply. Fortunately my N900 fixed itself yesterday (: , i didn't have to dissassemble it again to clean it. The bad news is i already ordered 2 digitizers from ebay ):
I have same problem but only when I carry N900 in my pocket...pressure on screen makes one spot on screen to remain "pressed" for 2-3 minutes. After 2-3 minutes, everything works just fine.
ps. I don't think it is software related problem...so I ordered new digitizer, hope it helps.
ps 2. This is what makes touch not working. I don't know if it's moisture inside of digitizer or it's the way it should be.
FYI, the screen is resistive, not capacitive, so when you touch the screen with your fingers It can sometimes register unwanted multiple inputs, and since the N900 is not multitouch, only one point registers.
You best bet is to use your fingernail or stylus to drag and click, especially in the corners, where it seems less accturate (to me anyway) and don't forget to calibrate every so often. Hopefully you can get your problem fixed so you can continue to enjoy the N900.
screen protectors also can make touch problems i was going to replace my screen and before that happen i discoverd the screen protector was kind of old and had some dust
I don't know that someone found solution for this problem, but I will write mine.
I had the same problem like dzano on his image. I didn't made pictures while repairing it but i will use his image to explain what helped my nokia n900. That spot means that you touching there, so i you don't want to replace digitizer with new one, you should make pressure on one side.
I have cut about eight pieces of plain paper the same size as sponge and glue each other, and placed them there, now my digitizer works ok, but it should be replaced.
