Physical buttons on E440 touchpad won't work after coffee spill: capacitive layer works fine

Question

Hi, can you help me with my stupid problem?
I have 2 questions:
1) Is there a way to enable trackpoint to work with the capacitive layer? I.e. to be able to use it without physically pushing the pad down. Now, as soon as I touch the trackponit, it disables light clicks (touches) of the touchpad, I guess to prevent unintended palm clicks
2) Is there anything I can do to make the buttons work again? (See the story below.) I have cleaned it all even inside, but there were almost no stains at all anyway, none on chips or cables. And it partially worked just this morning.
I guess I could soak it in water, then ethanol, and finally dig into rice grains for a week or two as a last resort...but I hope for a more electronics-friendly solution.
Story:
I spilled my coffee into the keyboard and touchpad, and even though almost no water got onto the motherboard (a few drops), I cut off the power supply in less than 10 seconds, and I cleaned it all thoroughly (even managed to get inside the touchpad itself and assemble it all back...what a pain), it works weird.
At first, it registered about 1/10 or 1/20 of physical button presses (depressions of the pad). So technically it somewhat worked. The capacitive (touch) layer worked fine including multitouch. Then I tried to just click on it repeatedly for about 100 times rapidly, and it started to miraculously work 100% fine...for about 30 minutes, then it returned to the 1/20 state again. But as soon as it started to work fine, the multitouch recognition died, so it wouldn't scroll etc. And after returning to the bad state again, multitouch was still dead. Then I tried to reinstall the drivers: multitouch has started to work (so scrolling and gestures are OK now). But the physical buttons appear to be absolutely dead at this moment, it won't register any click/depression at all. The capacitive layer works fine though, so I can still use it as a normal touchpad without physical keys.
But this renders trackpoint unusable as it requires physical depressions of the touchpad to register clicks.
Thank you very much!

Answer 1

hi, calleasto
sorry to hear about this mishappen. I recognize it, since it happened to me a few years ago, also my daughter pooring thee (not coffee - but the difference is marginal - ) into an external keyboard. I took it apart and cleaned and dried it very carefully, but never got it working again. This was an external keyboard.
a similar failure occurred to other people with they laptop keyboards (and to me, without "using" any liquid). I presume - without knowing really the interiors of the laptop keyboards - that (1) they are read out in a kind of matrix (sensitive bars arranged in rows and (almost) columns corresponding to keys), which needs two layers of contact strips; and that (2) the layers are separated by plastic sheets.
Your diagnostics seems to imply that
1) there are still bad contacts (might be liquid where it shouldn't be);
2) the contact point has shifted ;
The latter could perhaps be due to liquid shifting the pressure away from the point where it should be applied.
What i would do:
Give the keyboard much time for drying - perhaps by removing the keys again. But there is always the chance that the temperature of the coffee, and the residues are causing troubles and might cause some keys not to function properly.
I think (i am not sure !!) you have a "unibody": i think it is "unique " in the sense that it has no screws (except at the bottom) - and no Firewire outlet. I have never opened my MB, but the only way i see for opening it is from the bottom (there are 4 screws at mine) - but i do not know whether it is advisable to open it. I would check via Phone with Apple before doing anything myself.
Hope this helps.
Thomas