WHEN THE CAPS LIGHT FLASHES, AND THE A500 GURUS...  


                                by Phil Brew



   Ed: As usual, all disclaimers apply. If you don't know what you're doing,
  find someone who does.


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   The problem:

   This is a design fault from the factory, it also causes the 'CAPS LOCK'
  key to flash and freezes your AMIGA after the warranty has run out. The
  reason is that the circuit-board plate under the keys moves after a while
  and causes all sorts of problems.


   The solution:

   We are going to pull the keyboard apart and re-solder the keypad circuit
  sheet.

           You will need:  a clean place to work,
                           a clean sheet to work on (white),
                           allen key to void warranty,
                           a small phillips head screw driver,
                           pointy nose pliers,
                           masking (paper) tape,
                           soldering iron,
                           de-solder,
                           solder wire (thin),
                           and a cup of coffee.

   First flip the keyboard over (it should already be disconnected) and
  remove allen screws using allen key (funny about that).  Flippit (should be
  the name of a game) back over so it's facing you like normal and remove the
  top of the keyboard.

   You should now be able to see the keyboard wires going down that square
  hole cut in the metal cover (it's the RF shield believe it or not).  Using
  the pointy nose wires CAREFULLY pull the plug free, doing a little bit at a
  time on each side.  Write the the colour of the wire on the far left so you
  remember to put it back correctly.  Lift the keyboard free and place it
  where you can work on it.

   Flip it over and remove ALL the phillips screws, remembering to remove the
  four screws around the small circuit board last and placing them down in
  order, THEY MUST GO BACK IN THE SAME HOLE THEY CAME FROM.  If there is a
  cable tie securing the wires to the chassis, cut it off.  Don't worry you
  won't be using it ever again, because it puts too much strain on the wires.

   Flip it over so it should now be right side up and GENTLY remove the top
  section with all the keys on it.  Now you should be able to see a green
  coloured piece of plastic which flops around like an untrained seal.  Note
  in the top corner that it is soldered, also note that the holes in the
  circuit wafer (green plastic) do not line up with the holes in the board
  underneath.  That is the problem, because the plastic keys have black
  bridges under them which when pressed complete the bridge on the circuit
  wafer, so if it's mis-aligned the keys won't work correctly and the CAPS
  LOCK will remain lit and give you a system freeze.

   Using the de-solder and the soldering iron remove most of the solder that
  holds the circuit wafer at the top corner and lift the wafer off - DO NOT
  FORCE IT.  Next let it cool for about 30 seconds, now replace the circuit
  wafer so the holes line up.  Using the masking tape place pieces in the
  middle of the edge on each side so the tape can go under the lot and stick
  underneath.  Next ensure ALL the holes are lined up specially the ones up
  near the small circuit board and re-solder the top corner.

   Next replace the back to the keys and insert all the phillips screws - DO
  THE FOUR ON THE CIRCUIT BOARD FIRST, THEY ARE DIFFERENT SIZES.  Place the
  keyboard back in the computer and plug in the white plastic connector (did
  you forget which way it goes? I think it's black to the left, I did mine in
  1988).

   Now replace the casing GENTLY, plug it in, drink the coffee and and go for
  it.  Always remember to treat the computer with T.L.C. it is not shock
  proof.  Just an after thought, while you've got it all pulled apart, use a
  clean 1 inch paint brush and the vacuum cleaner and get rid of the, toe
  nail clippings, cigarette ash, dust and the resident cockroach.

   If you're into electronics you'll have no problems, if you're a novice
  take it easy and slowly, if you're half way through and you're not too sure
  just reverse everything you've done and put it back together and give it
  another go later on.


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