This is a short article on a lighter note.
I got a broken keyboard (from boxes with DOA stuff) with a few keys that were not working.
I've opened the keyboard up and marked the keys that were not working, you can see a slight red marker trace in the picture below:
The key circuitry is a sandwich of three flexible plastic layers: top and bottom with conductive traces and a middle one for isolation. Only the bottom one was broken.
Using a continuity meter the breakage was traced to an area near the connector.
As a heads-up, the measured resistance for this type of traces is 5-10 ohms/cm, so for a strip/trace longer than 20 cm the meter might not beep anymore.
I had some silver paste sitting around unused, so I covered the broken traces with that.
Some shaking required....
...after shaking all the silver flakes/powder should be evenly distributed. I don't think they mention this anywhere.
I believe a bottle of that stuff is around 15E for 5ml, but should last a really long time.
There's no way to properly construct traces, I've tried using toothpicks and other small-pointed objects:
I've left it to dry for 5 minutes then proceeded to remove the large unneeded areas with a cotton ball tip and traced the outline with a needle-like tip:
After 30 mins of drying and some more cleaning the keyboard was ready for use.
I got a broken keyboard (from boxes with DOA stuff) with a few keys that were not working.
I've opened the keyboard up and marked the keys that were not working, you can see a slight red marker trace in the picture below:
The key circuitry is a sandwich of three flexible plastic layers: top and bottom with conductive traces and a middle one for isolation. Only the bottom one was broken.
Using a continuity meter the breakage was traced to an area near the connector.
As a heads-up, the measured resistance for this type of traces is 5-10 ohms/cm, so for a strip/trace longer than 20 cm the meter might not beep anymore.
I had some silver paste sitting around unused, so I covered the broken traces with that.
...after shaking all the silver flakes/powder should be evenly distributed. I don't think they mention this anywhere.
I believe a bottle of that stuff is around 15E for 5ml, but should last a really long time.
There's no way to properly construct traces, I've tried using toothpicks and other small-pointed objects:
I've left it to dry for 5 minutes then proceeded to remove the large unneeded areas with a cotton ball tip and traced the outline with a needle-like tip:
After 30 mins of drying and some more cleaning the keyboard was ready for use.
Thanks for this posting. The information which you have provided is very good. Keep sharing such ideas in the future as well.
ReplyDeleteflexible membrane keyboard traders
It drives me mad, I repaired my keyboard already many times. It is indeed very hard to trace these which are close together. Better is to apply a larger area flat and then, as you did, use a tooth pick to trace the spaces in between. (Use a toothpick and an alcohol tissue). You also want a loupe if you do that.
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