Just a side thought, but you should be able to just "plug it in" (or probably honestly you could just press the battery into it's holes, just for a temporary connection), and measure the voltage at the pin on the clock chip or at the resistor with a multimeter. I had to do this on mine (had some issues with battery damage). Granted I haven't looked at the specs at all, but I assume at least the clock chip is the same on the German motherboard as on the standard? Purpose of this test is to verify that you're getting voltage at the correct location. Good luck!
