Few dead keys
 

One of my N900s have a few non-working keys, the Sym/Ctrl, the key beneath it and the Shift key, the T key and the Up and Right arrow key are dead, what could this be? I know it's HW related.

Re: Few dead keys
 

screw it open, and see if the 'dome sheet' is ok.

Also: Are you sure you didn't threw it in the washing machine? :p hehe

Re: Few dead keys
 

It had a small ingress of clean bath water once, but I did the right thing and removed the battery immidately after that and let it dry, it worked a few months after that but then suddenly my KB died partially.

Re: Few dead keys
 

Do the affected keys click when pressed? If yes, then it might not be the dome sheet but rather corroded contacts under it, possibly even caused by that immersion in the bath. It is easy to assume that the water started seeping in from the edges and the affected keys is as far as it got before you pulled out. The best way to find out is to open the phone and see.

Re: Few dead keys
 

So I can just remove the dome sheet without tearing it then?


EDIT: Removed it, cleaned with nail polish remover, didn't help :c

Re: Few dead keys
 

Ouch, nail polish remover?
Only use clean (medicine or pure) alcohol, e.g. from drug store (pharmacy).
And you should have done immediately after that incident. Now corrosion may have fulfilled its destructive irreversible work.

So if water comes to device:
pull battery immediately, open up device (always), check for water and clean with alcohol (take care of camera module), let it dry (do NOT use hair dryer) upright so water can rinse, maybe put it into closable box with silica gel or rice to let it dry for at least 24h (better 48h) and only after that power on again.

Re: Few dead keys
 

I put it on a hot radiator, worked fine afterward, but for the record: it's not a daily driver so I don't really care for it anymore, it's going on my bike as a computer+GPS later.

Re: Few dead keys
 

Also just for the record:
a 'warm' and more important a dry place is fine.
Hair dryers and/or "hot" radiators will produce too much heat and a lot of moisture. So sometimes a bit less is much more. ;)

And the 'bad' result may come up oonly after a few weeks/months.

Re: Few dead keys
 

Well, whatever your idea of hot is, how about lukewarm? don't remember properly.

Re: Few dead keys
 

Beter still, isopropyl alcohol. That's the stuff they use in CD/DVD lens cleaners... or indeed... <gasp>... some nail polish removers :) But be careful, some removers use acetone, which is a different beast, aggressive to most plastics as well as PCB protective masks. The smell should give it away.

A rule of thumb, if it is too hot for you to hold it, it is probably too hot.