Since I had opened the CDU to replace the faulty EXEC led I also decided to apply leds for the backlighting. I took four ledstrips and mounted them between two rows of swithces and kept an empty row between two ledstrips. From experience I know that these ledstrips give anough light to illuminate the whole display.
Because the whole print will be surrounded by a distance plate you will have to drill a hole through the PCB to pass the wires through. You have to take care that you don’t drill through print courses (on both sides) and also to drill the hole within the space for the distance plate which leaves not too much space for the hole.
After that I connected all the strips so they all can get their power. I use black for ground, red for 5 volt and yellow for 12 volt as is used in a PC power supply. This makes using the chance of a wrong voltage very slim.
And then the tricky part, assembling the unit. The trick is to support the front plate with a couple of objects. I used three pliers, but other object can also be used. Place all objects in such a manner that the bottom part with the keys protrudes over the edge of the table so you can easily mount the first screws. After everything is mounted again, this is the result. I am happy with it.