Connect the components to a DC-regulated power supply set to 5V and start with the lowest current setting. It can be even more difficult if all the board members are soldered on, and there is no way to remove them.
Set
your high voltage power supplies
to about 6V and connect its output terminals to your device. (If your device
needs 12V, set your power supply at least twice as high as that). A regulated
power supply is a great tool to use in these situations:
The
voltage can be adjusted over a wide range without changing batteries. It is
much safer to use than batteries because it cannot produce the large currents
that a short circuit on a storm could have (a fault condition). The output
terminals are usually shrouded, making it less likely that a lead could cause a
short circuit with the live or neutral mains wires if the information were only
connected to one of these terminals. Build a breadboard prototype, test each
component, and ensure they work as expected.