Master 128 Keyswitch Repair

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An intermittant BREAK key is causing trouble on this Master 128.
Probably just needs a clean. So first remove keys close to the faulty key for ease of access.

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On the PCB side, identify the joints relevant to the key being repaired and de-solder them.

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Moving back to the top-side, push a small screwdriver under the keyswitch to give some upward pressure,
then with another screwdriver push the securing clips in and the key will pop up.

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Lift the keyswitch clear of the board.

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To dis-assemble, using some pliers grip each pin on the base in turn and "unscrew" them.
Next part the 2 halves of the switch with a thin blade. Note some switches are glued together.

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Once parted, make sure not to loose the spring or any other parts.
Note how it came apart. Dont "rush" into any job.

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With the switch stripped, clean all parts with an alcohol based cleaning pen and re-assemble.

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Before re-fitting to the Keyboard chassis it is best to test the switch using a multi-meter.
It will save time if the fault was not remedied during strip-down.

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Push the switch back into the chassis and then on the PCB side re-solder the joints.

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Finally re-fit the keys and hopefully you will have a fully functional keyboard again.


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