N900 Touch Screen Has Stopped Responding To "touches"
 

So here is a bulleted chain of events prior to my touch screen failing to respond.

• have had my phone since February 2010
  
• have NEVER dropped it on the floor
  
• went swimming an hour before
• kept my swimming trunks on and dried out enough to sit in a restaurant seat
• put my N900 in my pocket with minimal dampness
• TOUCH SCREEN NO LONGER RESPONDS TO PRESS/TOUCHES that evening.

Here is what does work:

• phone and OS boot fine (after flashing because I was locked out)
  • Touch screen looks like new (virtually no scratches)
• touch screen has some sort of response but nothing predictable (just random touches SOMETIMES reacts)

This is what I've tried.

I've tried to re flashing using instructions on http://wiki.maemo.org/Updating_the_tablet_firmware without success.


So I've investigated a bit and it appears there are OEM screens I can purchase and there are youtube videos that make it feasible to replace. I don't have a problem investing in a replacement but I just want other people's feedback. Any feedback is greatly appreciated.

REFERENCE: http://youtu.be/pDQ81cahD1c

Re: N900 Touch Screen Has Stopped Responding To "touches"
 

I guess I'm hosed on this one.

If anyone can chime in this question I'd appreciate it.

Q: How can I tell whether the problem lays in the controller or the actual LCD touchscreen?


I will be thankful for any feedback. :):):):):)

Re: N900 Touch Screen Has Stopped Responding To "touches"
 

If you have a screen protector, just remove it. I had same problem and was thinking about software fault but problem was my screen protector.

Re: N900 Touch Screen Has Stopped Responding To "touches"
 

I did remove the screen protector but the issue is still there.

Thanks

Re: N900 Touch Screen Has Stopped Responding To "touches"
 

I'm going to disassemble it and verify all PCB flex cables are visually OK. I don't have a microscope so I'll basically do this with my 20/20 vision.

Re: N900 Touch Screen Has Stopped Responding To "touches"
 

Did you expose it to the direct sunlight/high temperature (you mentioned swimming)?

Re: N900 Touch Screen Has Stopped Responding To "touches"
 

i can confirm that its not your LCD screen that cause you this problem but the digitizer...replace the digitizer then your touch screen will be ok...
for all info it is not the LCD screen that is touchables but the digitizer that give the response on every touch...if you don't know what is a digitizer then google it...

Re: N900 Touch Screen Has Stopped Responding To "touches"
 

I think it would be more difficult to replace digitiser. Besides it is not offered as a spare part.

Do you know which digitiser did Nokia used in N900?

Re: N900 Touch Screen Has Stopped Responding To "touches"
 

actually your wrong...there a lot of N900 digitizer spart part out there...here in Malaysia you can get it at handphone repair shop or nokia center it self....the different is the price...you can also search at E-Bay or any online shopping websites...you will find it....

Re: N900 Touch Screen Has Stopped Responding To "touches"
 

Sounds like there could actually be moisture inside you screen assembly.

To visually inspect, dissassemble The screen assembly. I would go so far as to remove the LCD. I.E. seperate the LCD, DIgitiser and slide mechanism.

I highly doubt they have been physically damaged.

Leave these parts in a warm dry place over night. i.e. on top of the fridge/in airing cupboard/whatever.

Re-assemble and check to see if the problem persists.

If the problem persists that would imply the problem lies a little deeper. If that is the case, seal it all back up, feign ignorance and sell it on ebay with a vague clue 'the software screwed up'. Some N900 enthusiast will buy it in the hope that it only needs a reflash.

word of caution, the screws on the screen assembly are SUPER lightweight, do NOT over tighten them THEY WILL STRIP!

This is all assuming your phone is out of warrenty...

Re: N900 Touch Screen Has Stopped Responding To "touches"
 

Last time I cycled home during heavy rain, my phone got a bit wet (it was in my backpack but still).
Symptoms were like:
- screen does not always turn on
- touch does not function correctly
- phone boots correctly

like vi_, I would advise drying the phone by
- removing battery asap
- disaembling if necessary (makes it quicker)
- putting in a can with silica gel if necessary (makes it quicker)
- wait for 1 day or 2 (check every 12 or 24 hours if the phone behaves correctly, but don't let the battery in too long if it still doesn't)

Re: N900 Touch Screen Has Stopped Responding To "touches"
 

Before acting:

1. google for the service manual
2. read the manual, and determine which tools you will need
3. obtain necessary tools
4. work very carefully, the online video instructructor are very rough in handling, so be more careful

BTW: Good luck!

Re: N900 Touch Screen Has Stopped Responding To "touches"
 

same for me and it was the moderboard who was water damaged :S

Re: N900 Touch Screen Has Stopped Responding To "touches"
 

No, but it was in about 85 F heat.

Re: N900 Touch Screen Has Stopped Responding To "touches"
 

FYI, here is a service manual I found online.

Download Link as of 8-18-2011

I didn't believe it but there are actual parts called "digitizers".

see

Google Digitizer Search

So know I'm in limbo as to what to purchase, an new LCD or a digitizer.:confused::confused::confused::confused: :confused::confused::confused::confused::confused: :confused::confused::confused::(:(:(:(:(

Re: N900 Touch Screen Has Stopped Responding To "touches"
 

Also buy some extra screws, these are so small it isn't recommended to re-use the same ones twice.

Re: N900 Touch Screen Has Stopped Responding To "touches"
 

Have done a fair few of them now...think it looks worse than it is because the video was sped up.

Best advice I can give is use a really good screwdriver; WERA 006150 is what i use

Re: N900 Touch Screen Has Stopped Responding To "touches"
 

i have been facing a bit similar problem..
when i boot my n900 it starts fine but the touch screen is activated on its own,means even if i dont touch the screen it keeps on getting activated at a perticular point on the screen,its like sombody is repeatedly touching the screen at that point, also the battery gets depleted very fast and the back side of the phone get quite warm. PLZ HELP:(

Re: N900 Touch Screen Has Stopped Responding To "touches"
 

I found a digitizer screen for about $20 on Amazon and replaced it. When I first booted it, the touch screen was working erratically then stopped again.

Once again, no response to my touches after the phone has been on for about 10 minutes.

Re: N900 Touch Screen Has Stopped Responding To "touches"
 

This is very dissapointing. Before this occurred, I was under the belief that Nokia handsets were the best in the world. I know have backed off from that belief. I spent $560 USD and waited over 1 month for this device to get delivered to me. For this price I had expected the phone to last at least 5 years of daily use (just like my Blackberry and my cheap Samsung) but it has not. My last hope will be to mail the entire package to Nokia and express to them how they will loose a loyal customer.

I'm totally bummed-
:(:(:(:(:(