I've been having a really weird problem with my protoshield in terms of actuating the fans. I've been fiddling with the fans for a while now, and I can't seem to get them to work. The fans are wired correctly in terms of polarity in the grove connector. The Relay board is working fine, and the Arduino is outputting the correct voltages from the correct pins (14 and 15, since hookup wire directly into the grove connector from the arduino turns on the relay and therefore the fans as expected). However something may be wrong with my protoshield. I have tested sending signals through the pin and out a grove wire attached to the connector with success, but for whatever reason when I plug the protoshield into the arduino and try to actuate the pins, the signal never gets to the grove socket! I'm incredibly confused, as when I supply voltage to the bottom of the pin (in the female header on the arduino) and try to test hookup wire attached to the top (on the side with the grove sockets), I can't even locate the signal.
Is it possible that my headers are 'defective' or that I have somehow accidentally created a cold solder joint? Please let me know if you've experienced the same