[Coco] Fixing coco2 keyboard traces.

cralt at comcast.net cralt at comcast.net
Sat Jul 21 23:12:07 EDT 2012


I saved a lowly 16K Coco2 non-ECB from a poll barn. It was in ruff shape but I cleaned it up and got it working. The keyboard was totally full of trash so i spend the morning dissembling it and washing each part off. It all went back together good but only has a few keys working. I swapped keyboards with another coco and verified it is the keyboard that is the issue. The issue seems to be the ribbon that exits the keyboard. If I bypass this with jumper clips I can get the keys to work. It seems the resistance is higher on the traces on the exposed ribbon section then it is on the traces that are in the keyboard. I can also see light through the traces on the ribbon section. 

I tried coloring over the tops of the traces with a #2 pencil but it didnt help. It seems the coco wants to see zero ohms before it registers a keystroke. Its only seeing 4-5 ohms through the bad traces. 

Is there any way to rebuild the traces or some how attach jumper wires to the membrane? I dont think I will be able to solder to them with out melting the plastic. Any one have any tricks to fix this? 

Thanks 
-chris 



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