Sharp PC-1600 keyboard issues

[tony duell]

> 
> I'm more concerned about disconnecting the membrane from the PCB (the
> PCB is on pg. 41/42, the membrane on 45/46 -- you can see on the lower
> edge the connections made between the two) as I'm not sure how the two
> are held together -- there's a metal bracket on top that sandwiches the
> two together (and is screwed into the "front" of the machine -- see
> parts 20/21 on the exploded disassembly).  I'm afraid if I take the two
> apart I may never get them back together making good contact again.
> Have you dealt with anything like this? Anything I should be concerned
> about?

I wouldn't separate them unless you have to, You may well find they are 
lightly glued or even soldered, if so, do not separate them at the start. Of course
if the membrane comes off when you undo the screws then it is intended that
it is separated during servicing, so no worries.

When you have the PCB out, then do a continuity check on the signal in question,
Even if you find it open, make sure the 'open' is at the junction of membrane and
PCB, not an open track on one or other.

-tony