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Photon · 23 September 2009, 20:56

Well, I thought I fixed it. It worked perfectly for a couple insertions, then some keys started failing again. The strips on my keyboard cable had been very worn down by the connector (I shone a flashlight from the back and saw almost all stripes let light through them).

And applying conductive silver made everything work, except - some Alt and Amiga keys failed again after a while, when the ZIF socket blades had easily scraped the conductive silver from the "holes" in the strips.

My solution:
I cut off 1cm from the cable, took some duct tape (any strong-fastening tape will do), and ripped off the tape in the direction of the strips (ripping perpendicular didn't remove any green stuff). I made a very light cut across the cable where the green stuff should start getting ripped off, beforehand. Make sure you don't cut off the stripes! Anyway, after I ripped off the tape the green stuff didn't come off exactly at the cut anyway, so mainly the cut is just for making the last 1 cm of green stuff be detached from the rest of the green stuff above 1cm. (Crap wording, hope you know what I mean.)

When the strips were exposed, I carefully painted the strips with a tiny brush with conductive silver to protect them, and made sure there were no shorted stripes by measuring with a multimeter and carefully scraping off conductive silver between the shorted strips. Use a light hand, it's easy to go non-straight and scrape off the silver on a stripe! The silver sticks permanently to the strips, but comes off easily with a thin radio screwdriver, or in my case, carefully scraping with the back of the tip of a scalpel ("Xacto" knife to Americans?)

The conductive silver laquer was a bit thin, but the "settled" stuff on the rim of the bottle was a bit thicker and was easier to apply with the brush.

The brush was a super tiny artist's brush from a store that sells pens and papers and stuff. It wasn't easy to apply even if the brush was perfect, but it was much easier than with the toothpick, because the brush would hold the laquer better so I could paint 5 strips per "dip", and it was easy to scrape it off a little to have a proper amount in the brush, and not a "blob".

I double-folded some duct tape and put it in a clamp to hold the cable steady - but if the keyboard is loose, you could tape it to a table, that should be easier.

I put the silver about 3 mm to 10 mm from the end of the stripes, since that's where the ZIF socket blades clamp.

I tried a thin piece of Scotch tape on the back of the cable before I made the above solution. But I don't recommend it, it only wears out the stripes sooner. If it doesn't work without it, it's more likely that you have some more work to do on the cable than that the ZIF socket doesn't clamp hard enough.

After applying the silver stuff, I tested each stripe with a multimeter so that the silver really did have 0 resistance to the unpainted part above the silver on the same strip. The silver stuff reacts strongly with the case of the plastic, so have some paper at hand if you should spill a drop. It also smells like nail varnish and should be very hazardous to your health, so do it on the balcony or open a window when you're done. Dangerous stuff, wash your hands after.

Sorry for the silly level of detail of this description

but it really isn't as easy as "apply silver with a toothpick".

23 September 2009, 20:56	#12
Photon Moderator Join Date: Nov 2004 Location: Eksjö / Sweden Posts: 5,639	Well, I thought I fixed it. It worked perfectly for a couple insertions, then some keys started failing again. The strips on my keyboard cable had been very worn down by the connector (I shone a flashlight from the back and saw almost all stripes let light through them). And applying conductive silver made everything work, except - some Alt and Amiga keys failed again after a while, when the ZIF socket blades had easily scraped the conductive silver from the "holes" in the strips. My solution: I cut off 1cm from the cable, took some duct tape (any strong-fastening tape will do), and ripped off the tape in the direction of the strips (ripping perpendicular didn't remove any green stuff). I made a very light cut across the cable where the green stuff should start getting ripped off, beforehand. Make sure you don't cut off the stripes! Anyway, after I ripped off the tape the green stuff didn't come off exactly at the cut anyway, so mainly the cut is just for making the last 1 cm of green stuff be detached from the rest of the green stuff above 1cm. (Crap wording, hope you know what I mean.) When the strips were exposed, I carefully painted the strips with a tiny brush with conductive silver to protect them, and made sure there were no shorted stripes by measuring with a multimeter and carefully scraping off conductive silver between the shorted strips. Use a light hand, it's easy to go non-straight and scrape off the silver on a stripe! The silver sticks permanently to the strips, but comes off easily with a thin radio screwdriver, or in my case, carefully scraping with the back of the tip of a scalpel ("Xacto" knife to Americans?) The conductive silver laquer was a bit thin, but the "settled" stuff on the rim of the bottle was a bit thicker and was easier to apply with the brush. The brush was a super tiny artist's brush from a store that sells pens and papers and stuff. It wasn't easy to apply even if the brush was perfect, but it was much easier than with the toothpick, because the brush would hold the laquer better so I could paint 5 strips per "dip", and it was easy to scrape it off a little to have a proper amount in the brush, and not a "blob". I double-folded some duct tape and put it in a clamp to hold the cable steady - but if the keyboard is loose, you could tape it to a table, that should be easier. I put the silver about 3 mm to 10 mm from the end of the stripes, since that's where the ZIF socket blades clamp. I tried a thin piece of Scotch tape on the back of the cable before I made the above solution. But I don't recommend it, it only wears out the stripes sooner. If it doesn't work without it, it's more likely that you have some more work to do on the cable than that the ZIF socket doesn't clamp hard enough. After applying the silver stuff, I tested each stripe with a multimeter so that the silver really did have 0 resistance to the unpainted part above the silver on the same strip. The silver stuff reacts strongly with the case of the plastic, so have some paper at hand if you should spill a drop. It also smells like nail varnish and should be very hazardous to your health, so do it on the balcony or open a window when you're done. Dangerous stuff, wash your hands after. Sorry for the silly level of detail of this description but it really isn't as easy as "apply silver with a toothpick". Last edited by Photon; 23 September 2009 at 21:32.