Need your help guys, I took out my N900 to use but noticed that its buttons are falling off.. I do not want to mess it up by using super glue or similar..

Need your suggestion what is the correct way to stick the buttons back without damaging .

Also.. the buttons are getting offwhite any suggestions on fixing that too.

Thanks in Advance.

I think you need indeed a more flexible bond, super glue is indeed too hard.
Maybe a small drop of epoxy glue spread sparingly and evenly?

Problem with "epoxy 2 component" glue is that it is expensive for small quantities and if you want to use it wisely you are forced to find a whole range of things to glue in one go in order to spend it wisely.

If the buttons are getting white: stop using finger nails and keep those nails short?

Or maybe try a less destructive means: some square of high end double sided tape?

I used superglue in the past in cases like this. With no issues.

The way I see it, the buttons are rigid. So glueing them with something that sets rigid is not an issue.

That depends on how it's packaged.
About 20 years ago my father bought some 2 component glue that came in two separate bottles, each holding about 100ml. Both bottles are about half-way done and we're still using them, by putting an even amount of both on a piece of cardboard and mixing them manually with a match or a toothpick.

I guess what you should avoid are those super-fancy apparatuses, that hold resin and hardener in separate compartments, but readily mix them in a common valve, because that valve will just get clogged up. Usually there will be one or two spare valves included, but you'll run through them faster than you'll run through the glue.

Watch out for the thickness of that tape! There's not a lot of spare room between the keys and the display if the device is closed.
Also I believe it would be difficult to cut and apply such small squares of reasonably sticky double-sided tape, without gluing the keys everywhere but where they belong. But maybe that's just me being all thumbs.

2 part epoxy works just fine .
Easy to use.. and to get the best calculated amounts of both parts ..
Find the 2 part epoxy in syringe format.
You can do whatever small or great amount ...without waste...and cap the syringe afterward ..for future usage

Hmmm...
Keys turning white...
And falling off ...you say?
Not too uncommon or unusual...
Sounds like your n900 has a case of "Nokrosy".
Nokia Leprosy as I understand it.
With proper treatment you can stop its spread before the n900 "goes terminal" and the entire slide out falls off...

I'd say the superglue treatment is a temporary fix at best and what you should do is get a replacement keymat!
There have been such spares available until quite recently I think, or you might be able to salvage one from a broken not-so-used device.

Not really a solution but for the remaining black keys:

Before the black paint/plastic (black layer) goes away after becoming every day thinner, I put nail varnish (transparent is better )on the keys.
It dries fast and is not really clean and elegant BUT very resistant.

White keys:
I'd try to put black paint/varnish on the white ones and carefully scratch the symbol to reveal the white only there.

Best

I might have a spare keymat somewhere from a totally dead N900, hmu in PMs if interested, it's yours as long you pay shipping.

Thanks a lot for your response friends. I will go with epoxy and hope the keys will stay there without melting the inner rubber. I wonder what Nokia used to hold the keys at the first place.

Yes my Nokia N900 is in a rexine cover from day one. Could that be the reason the keys are falling off?

Thanks again for your quick and helpful replies..