🚀 go-pugleaf

To Peter Jaspers-Fayer

Make sure all cables and wiring are connected securely, sometimes they vibrate
loose.
If that doesn't work, unplug the circuit cards and replug them in.  Sometimes
all the contacts are not making contact and the boards need to be reseated.
Make sure you ground yourself before (and occasionally while) you are handling
the boards to avoid damaging the boards with static electricity.  This is 
probably rare but if it still doesn't work, at least you know you haven't
added anything to the problem.  You can ground yourself by touching a cold
water pipe or the screw that holds the cover on a conventional wall socket
plate or switchplate..
Come to think of it, check to see that any socketted chips are seated properly.
Sometimes all the chip pins are not making good contact.  Also look for solder
bridges or conductive dirt shorting circuit traces or chip pins.