2.2.3 Fitting The MIDI Upgrade Board
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Using a permanent pen place a mark on both parts of the connector. This will help you
replace the connector the right way round later on.
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Unplug the cable from the keyboard PCB.
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Using a small cross point screwdriver remove the screws that hold the PCB to the plastic
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keyboard frame.
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Slide the PCB towards you so that the 37 spring contacts slide out of the keys.
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Place the PCB on a flat, firm surface.
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With a medium sized flat screwdriver carefully prise out the large M110 chip from its
socket. The best method I have found is to lever it up a little bit at each end in turn, slowly
working it out of the socket. Put the chip is a safe place.
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Turn the PCB over.
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Desolder the IC socket used for the M110.
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Fit the new IC socket. Solder each pin, making sure there are no solder bridges or dry
joints.
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Remove the six 5k6 resistors (blue green red gold) that sit next to each other in a row next
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to the IC socket.
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Re attach the keyboard PCB to the keyboard frame. It is a fiddly job as all 37 key contact
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springs must be re aligned with the small holes in the keys. Any springs which are not
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seated in their locating holes can be fitted with long nosed pliers, making sure you do not
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squeeze too hard and squash them.
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With the keyboard on a flat firm surface bring the MIDI Upgrade board to sit on top of the
keyboard PCB. It should be arranged so that the connecting wires follow the same
direction as the connecting cable disconnected earlier. The photo below shows the general
arrangement (this is an older version of the MIDI Upgrade but the alignment is the same).
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