Vintage Synth Repair

--- In vintagesynthrepair@yahoogroups.com, "inocencio66" 
<paulo.simoes5@...> wrote:
>
> My SH-101 was in worst shape than I thought: broken copper traces 
near  
> one of the keyboard matrix connectors. Reflowing the solder joints  
> didn´t do any good as it quickly melted the phenolic (or whatever 
> material is the PCB made of) and the traces jumped off. 
> 
> As the keyboard contacts are of the conductive rubber type, the 
copper 
> traces lead to what seems like conductive carbon ink pads, so 
there´s 
> nothing solderable to run "oops wires" from. 
> 
> One possible solution might be removing the varnish at the 
connector 
> end, exposing enough solderable copper area. What can be used as 
> solvent?
> 
> There is also one special silver ink pen that I could use to redraw 
new 
> traces directly from the carbon pads, but how well would the ink 
bond 
> to the pads? I coudn´t measure the carbon´s resistance, let alone 
any 
> signs of continuity... 
> 
> Do you know of a more conventional way to do the repair?
> 
> Any advice would be greatly apreciated.
>
Just use a sharp X-acto blade a carefully scrape tha solder mask of 
down to the bare copper,then tin the traces.Good old 30 ga.wire wrap 
wire is perfect for trace repair.
                 Jim