I've connected the display via an external power supply capable of 12V - 4A.
It was coming on intermitently...
Turns out the small power converter board was not soldered on it's 4 corner points.
Soldered those 4 points and now it's steady going on and staying on.
Next I noticed the display would not do anything other than displaying the various colored squares and the text "PIN2DMD Virtual Pinball".
After 3 minutes the serial number came on and switched between "not activated" and the number.
Wrote down the serial number and made a donation as per instructions.
I've got the activation key some time later.
Now I needed to connect the display to a laptop to activate it.
As soon as I connected the display via the mini usb cable, it turned on.
So no special power supply needed I guess...
I'll see if I can connect the display to J140.
If only I could make to computer communicate with the display to activate it.
My laptop has Windows 10 and is having a hard time finding it.
I even tried to install the special usb driver program, but no succes jet.
I will again try today.
The weather is good, so maybe I'm lucky....