I'm going to be using an old IDE cable when connecting the upper and lower halves of the aluminum case. There should be more than enough wires in the 40 pin cable to carry HDMI, USB & power. To do this we need to dismantle and connect the HDMI cable. I went and bought two from the £1 shop in case I screwed one up.
Measure an approximate length of HDMI cable from the LCD logic board to the bottom of the wood panel.
Very carefully cut around the plastic sleeve of the HDMI cable. You should then be able to pull the sleeve off the wiring.
Cut around the molding of the HDMI socket. Make sure you don't catch any of the wires. I have used a small piece of heat-shrink at the plug end to help support the loose wires.
Using some spare IDE cable connect four wires to both the WiFi PCB & the Bluetooth PCB. Use the red pin 1 indicator as the +5v wire. Fit the ends with DuPont connectors
Separate the wires from an IDE cable. Strip the ends to show bare wire, tin the wires with solder and place small lengths of heat-shrink over the wires. I have put the cable into a vice (with rubber grips) to hold the cable while soldering.
There are 15 wires for the HDMI, 2 for the power supply, and 8 for the two USB PCBs. They all need to be soldered onto the IDE cable. I started with the HDMI. It is worth putting some heat-shrink over the wires to help with running the wires later,
Use 3 wires for the +v supply and another 3 for gnd. Make sure all connections are protected with heat-shrink.
Fit DuPont connectors to the IDE cable for the USB PCBs. I have marked one line on each with red heat-shrink, this will be used to correctly orientate the plug and socket so there are no crossed wires.
Connect up all the wires making sure it all plugs in OK.