Final Assembly

Note that this page assumes you are using a production case. For a DIY-constructed case, you'll need to work out how to assemble it yourself.

Once you have finished populating all the PCBs, they should be mounted to the front panel and lower case using the M3 screws supplied, except for the pot boards which are mounted on subframes and then attached to the panel with nuts on threaded shafts.

front panel board mountings

The main and I/O boards are fitted to the lower case. A short ribbon cable should be made to connect these boards - around 50mm of ribbon can be folded to give something to pull on when the cable needs to be removed:

click for larger image

The power socket and switch are mounted directly to the lower case, and wired as shown:

I use a 2.1mm connector for power input, wired for centre positive polarity. You can reverse the polarity to suit a different PSU if you wish. The switch can be wired to break either of the power supply connections to the main board - I tend to always wire it into the positive line.
Pin 1 of the power connector (nearest the left edge of the board) on the main board is ground (0 volts), pin 3 is the positive (or AC) supply.

To connect the front panel boards to the main board, you will need to put together a set of three 16-way ribbon cables, a single conductor lead for the function key board and a four conductor lead for the DATA and TEMPO pot board.
This image (click for full size) shows the lengths, and connector positions, for each of the pot, switch and PLED ribbon cables. Note that the red wire indicates the pin 1 connection, and should always line up with the arrow on the connectors. Pay careful attention to any connectors which are reversed on each of the cables.

ribbon cabling

The cable lengths are kept to a minimum to prevent noise pickup or transmission. This makes it a little bit awkward to fit the cables to the main board and close the case unless you do it in the right way. Sit the lower case on a flat surface, then place the front panel on top so that the upper pot board sits against the back edge of the lower case, and the front panel is 'hinged' up at the front. From this position, all the cables can be attached, and the front panel then closed.
This picture shows the cables in position, with the front panel sitting at an angle further inside the case:

ribbon cabling attached

Once the cables are all connected, the case can be closed, and your P3 tested.

Remember to carry out the memory initialisation the first time you power up a P3.
Hold the F1 and step 7 keys while powering on, then when the 'Wiping ALL Data!' message appears, press F1 and F2 simultaneously to confirm.
You should then be asked to select the memory layout - 6x8 is the recommended setting, but this can be changed later.

If your production case has been supplied with wooden end cheeks fitted, you may like to remove them until you have assembled, tested and carried out any troubleshooting on your P3, to reduce the risk of damaging the wood finish while your unit is on the workbench.