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PowerBook 190cs with faulty keyboard

toples50

6502
I bought a PowerBook 190cs for my collection, for about 40 euros..Starts up normally(System 7.5.2) but the keyboard does not work.(in fact the caps lock lighting its ok-only this...).

 
The 190/5300 keyboard is similar to the Duo keyboard in that it has 2 Mylar sheets with a circuit painted on it made by conductive paint. The conductive rubber ring on the keyboard button completes the circuit when pressed against the Mylar sheets. Chances are the previous owner spilled soda or coffee on it and sugar coated the conductive mask.

You can remove the keyboard and dunk it into a warm distilled water / alcohol mix (8 parts water to 1 part alcohol, which is about 1 gallon of water and 1 – 16oz. bottle of alcohol) Then dunk the keyboard into the water and slosh it around a bit and then let it sit for a long time. Slosh it about again when you are about to remove it. Then rinse out the keyboard with distilled water alone and then chase it with alcohol (alone) to help remove the water from the surface.

Warning: If you use tap water, you will kill the keyboard! The minerals in tap water will react with the painted wiring on the Mylar sheets and you will destroy the wiring when the minerals react on the wiring. Do not use Filter water either, as filtered water still has some minerals in it. ONLY USE DISTILLED WATER!

 
Just in adding, as there is no way to edit this past the Time Limit...

A few members have washed their logic boards in tap and filtered water and ended up with a board covered in this fine white dust that was difficult to remove. Sometimes it interfered with the board, other times it did not as different posters live around the world and their water contained different minerals from others.

For the keyboard mask, depending on where you are, the minerals in your water may or may not react with the painted conductive surface of the mask, with a high chance of it reacting. Why risk it? Better to spend the extra $2 - $3 on getting a couple of gallons of distilled water from the dept. store.

 
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Nothing happened.I have washed the keyboard with distilled water and I have tried to put it again back without luck.Keyboard seems dead.Only the caps lock lighting works.Where can I find a replacement keyboard for 190?

 
ebay is probably your best bet, though you might be looking for a while.

It might be worth looking over the key matrix - and the keyboard ribbon - for any breaks and patching them with a conductive ink pen.

 
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Quite often there are untested 5300s on eBay which a lot of times are just untested/as-is because of a lack of power adapter. It would probably be easier and quicker to pickup one of those instead of waiting to find just a keyboard.

 
I probably have a spare 5300 keyboard, but the layout will be different (it's a french keyboard) don't remember your one, but is a working unit.

 
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