Keyboard repair after spill

[r2d2]

A little while back, I accidentally spilled Coke on my keyboard, Microsoft wireless 800 wireless keyboard, and ever since, a few keys had stopped working. It is a waterproof keyboard, so I don't know why it's not working.
Even right now, I'm using speech recognition to type this out.
I've tried cleaning the keyboard by pouring water on it, but that did not help. When the Coke first spilled on it, it had spilled onto my CPU as well, and thus I had to clean it first, and so the Coke got time to settle onto the circuitry of the keyboard.
Then, a few days later, I tried cleaning the circuitry of the keyboard using rubbing alcohol. When I opened the keyboard, there were three layers of plastic each of them stuck to one another using two something that seems like pressurised locks. Then on top of it, was rubber with the key spots or buttons which is what actually presses against the circuitry, pretty much like television remotes, other than the part that here we have plastic circuitry. Then there is a circuit board which also connects to the battery and the keyboard circuitry. I cleaned the Golden contact points on the circuit board as well. But when I put it all together, it was still like before, all the keys which weren't working before did not work anyways.
So last night, I left the upper plastic casing, which has all the keys, the rubber part, and the plastic one with the circuitry, in water, so that the Coke could come out.
Also, the plastic part I'm talking about looks like this: http://alexpb.com/notes/wp-content/uploads/2008/12/keyb...
now, when I put it back together, it is not working at all.
Someone please tell me what to do about this now.
I need to get my keyboard working again somehow, as I cannot get a new keyboard which will be even half as good as this one. Please help me.

 

[(*steve*)]

Do this ASAP (i.e. before the coke dries onto a gooey mess)

1) Remove all batteries

2) Dunk the entire keyboard into a bucket of water (or a bath, or whatever it takes). One or two dunks are all it will require if you do this in the first 10 minutes or so after spilling the coke. (if you're pressed for time just throw the thing in a bath or under a shower, or a running tap -- water will probably do less damage than coke)

3) Prepare a mixture of 50% methylated spirits and 50% water. Dunk/dip the keyboard in this. This will displace most of the water and will evaporate quickly.

4) Spray any circuit boards and electrical contacts with isopropyl alcohol

5) Allow to dry in a warm place for a day or so.

6) When absolutely dry, replace batteries and pray to the deity of your choice.

If you've left it long enough that the coke has started going sticky, then it will be harder. You'll have to take the device apart and instead of just dunking it (step 2) you will have to clean it as thoroughly as you can. Cleaning under ICs (especially surface mount ICs is not trivial.

However, in your case, I recommend buying a new one.

 

[duke37]

Phosphoric acid is corrosive. Put a cupro-nickel coin in Coke and leave it for a while and see what happens.

 

[Raven Luni]

It's probably the conductors on the membrane. I spilled beer on one a few years ago with similar results. They are extremely thin and can corrode almost instantly - so a combination of acidic liquid and current where its not supposed to be will do that.

To repair:

- Disassemble the keyboard and remove the membranes (for a MS keyboard they will usually be in 3 layers).

- You will be able to see any corrosion right away. Take a fine scalpel and scrape away any areas that look too far gone

- Get some conductive paint (you can google for this) and rejoin the lines where the connections have been cut

- Reassemble (once the paint drys) and hope for the best.

 

[Sadlercomfort]

WD40 a multi-purpose spray that is a great at cleaning up corrosion on metal contacts, I've used this before when cleaning keyboards, and other corroded contacts

 

[Raven Luni]

WD40 a multi-purpose spray that is a great at cleaning up corrosion on metal contacts, I've used this before when cleaning keyboards, and other corroded contacts

Handy for the actual contact points, but if the actual lines are corroded to the point where they wont conduct then they need redone.

Anyway - for r2d2 and anyone else unfamiliar with keyboards, here are a couple of of pics I took since I'm actually in the process of butchering a cheap keyboard for another project. You can see the 2 sheets with the conductive paths. These form a matrix and when you press a key it connects the points of 1 column and 1 row (which means fewer inputs then having one for every key). These conductors are simply a thin metallic substrate. The contacts for the PCB are simply clamped on to ensure physical contact. You can repaint these lines with metallic paint where they are too corroded.

 

[garyson0]

Rinse with Deionized water

1. Rinse with deionized or distilled water. Many people prefer to rinse with deionized water over tap water. Regular water will leave deposits that can cause electrical shorts, but deionized water will rinse clean, dry, and leave nothing behind.
   
2. Use paper towels or any absorbent material that is lint-free.