I have a PCB printed based on a design that I also have on a breadboard. The breadboard version works dependably and the PCB does not! I originally thought that my issue was software and posted this thread before realizing that the software was fine after resurecting the breadboard version: http://forum.arduino.cc/index.php?topic=294463.0
The circuit is based on a Nano interfaced with a 1.8" TFT display (with SD reader) and for testing purposes a DHT-11 heat sensor. The behaviours that I see on the PCB version include the DHT-11 not always working and more often the SD reader failing to close the file properly (though it does save data to it that can be read back up to a point where even that fails).
I am not even sure where to begin to diagnose this. As far as I can tell all the conductors are the same between both designs. I am going to start with measuring some resistances point to point between the two boards. Same with voltages.
Any suggestions on how to figure this out would be appreciated. Hardware is not my strongest point!