This afternoon I took the EFIS (from Open Cockpits) out of its original housing. Again the USB wires are soldered. I had to desolder them to get the EFIS out of its housing and later soldered them back on.
Since I want to be able to dim the backlighting I took a look into its connection. It appeared all the leds are connected to pin 1 and 2 of J2. Since I still had a 10-pin extension cable lying around I cut the first two leads. In the picture you see that lead 1 is cut, later on I also cut lead 2 so I can attach a PWM dimmer later.
And in this picture you can see the EFIS mounted in a part of its original housing again (including the mounting panel for the MIP) so it can be used again for flying. Later on I will get the mounting panel off and screw it in the MIP again.