[sdiy] Chroma Polaris Membrane Switches

[Tony Clark]

   Hi List,

> Those of you familiar with the Chroma Polaris will remember that it has
> those troublesome membrane switches which fail too easily and are very
> impractical to repair.

   While this is a common problem, it's not as hard to repair as most 
people think.  It _does_ require someone who's quite skilled in 
soldering, but beyond that, it's not that bad.
   As is typical of membrane switch panels, the signal lines are plated 
to a flexible plastic carrier.  In the Polaris, this connector is bent in 
a 180 degree loop to the PCB.  Unfortunately this plastic has become 
brittle over the years and due to the forces exerted on it due to the 
tight bend, have typically cracked, taking with it some of the plated 
signal lines.
   What I did to mine was to cut the ribbon cable where the crack 
occured.  Then use a sharp knife to scrape off the protective layer 
covering the traces.  If done correctly, you can actually solder directly 
to these traces.  if this is too difficult, you can utilize a conductive 
epoxy to attach normal wires to these points.
   Afterwards, you can either solder the new wires directly to the PCB, 
or install a new type of header and connector (I used an AMP 0.100 spaced 
right angle header).  I then GLUED the ribbon cable down to the case so 
that it will no longer bend or flex (hopefully removing any further 
chance of cracking).
   Fixing it was no small feat, but certainly cheaper and easier than 
doing any sort of custom setup.  If someone was of a mind, they could 
easily buy up all these cheap Polarises and turn a decent profit by 
repairing them.

   Cheers,

   Tony

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