I've had it two years now - and love it. (Can't find another phone on the market that I would replace it with... come on Nokia get your focus right again!)

In the last 5 days a flicker has started on the screen. At first it was just the app switcher screen - but then it was in the desktop too - unless I change the background... and now in some apps - but not all.

Here is a short youtube video clip that shows what it looks like http://youtu.be/VcRMpIAJ5fM

And a longer one here: http://youtu.be/VpX6VDfPtA8

And some images here:


It's running KP49 and CSSU - but not speedpatch blah blah...

Linux Nokia-N900 2.6.28.10-power49 #1 PREEMPT Fri Nov 18 23:59:53 EET 2011 armv7l unknown

So any ideas what is causing it and how to fix it?

I remembered a similar thread with a pic looking a little like yours.
Post nr. 3 seems promising
Hope your probs will end by saturday

Thanks Peter - I had seen that thread but it looked like a slightly different problem to be honest - or maybe worse. But then my machine is gettining worse all the time.

I had that problem the day I tryed h-e-n
It lasted even with reboots
Half an hour later, it was gone
Most unexplainable and fu*ked up problem ever
sorry but I can't help you, it seems that N900 works with great programming and black magic too

Looks like dying GPU or bad screen/screen cable. ( unfortunately dying gpu seems more probable as it does it only in some apps, when the screen is refreshing I think )
Can you use TV-out to see if the problem continues?
If not, you can take a screenshot with ctrl + maj + p and see if the problem show up in the screenshot.


Edit: The second video is now up and it's looks like related to what colors are displayed, it may finally be just the screen.

Hi Megaltariak. I was really hoping the (particularly) DSP and the screen cable could be left out of this thanks very much

Screenshots are fine - hence I had to use a camera to show the problem, and I'm working towards the two hardware possibilities you've mentioned.

I should mention, I get the flicker in bootmenu - with KP49 and the stock Nokia kernel - so I'm fairly sure it's not software related - but could there be something needing reset in the DSP? It's clearly ok for some screens.

It seems to be colour at one or a percentage of the screen that is the trigger. Mostly white screens seem ok. Dark screens are generally bad.

Also been playing with the CABC settings - no affect on the flicker though.

Do hope I've not overcooked the DSP with one of the OC profiles.

(Left the battery out overnight last night to see if that would allow anything to be "reset". No help at all!)

sr00t: I wish my problem would just disappear too - you so lucky!

Overclock? I once had graphic corruption during the transitions while my N900 was overclocked, went away with a reboot but quickly returned, going back to stock speeds made it not happen again.


Also, just in case, try shaking your N900 a bit hard and see if the issue goes away or change, who knows, might be a loose cable or somthing.

I'd bet its a loose cable, though as others have mentioned it could be the DSP or the screen itself. May be worth finding the disassemble video and taking it apart just to the point of getting to the screen connection cable and trying to pop that out and back in. If you jarred it recently, that could have caused a cable slip...

Had the screen assembly off and cables seem fine.

Overnight it got worse.... but I've put a light blue theme on and can use most windows...whenever there is black down the right hand side it seems to lose lines causing the flicker. Very odd, but I'm fairly sure its the DSP now. Sigh!

If you live in the UK, PM me your address, I will mail you my old LCD. It has slight distortions in on the back light spread (like all old n900 LCDs) however it does work and would let you eliminate the LCD as the problem.