PS: Before you buy another Arduino board, get a better DMM
and to my surprise, it showed voltage!
Not related to the observed phenomena but maybe interesting for Pracas the paperduino:
You may get conductive ink if you mix it (worth a try) with the content of this
That's a bit pricey for only 7ml!
A cheaper alternative is to use staples.
you can see in the last image, all the component leads are soldered together "dead bug" style