Fez Domino gets really hot

Our Fez Domino’s are getting really hot when using a 12V adaptor 500 and 600mA.

They will be plugged in 24-7.

Will this burn the board up?

What is the best power supply to use for external use?

You have several Dominos that do the same thing? How much current are you drawing through them? 12V is a little overkill, but should be okay. Some heat is expected. Can you measure the actual temperature? Other than this, do the boards behave as expected?

The Domino is a 3.3V board, so a (reputable) 5-6V 1A switching power supply (If AC) is all you need.

Actually, a more ideal solution would be about 6.5VDC and capability to 1A, depending on how many other peripherals you have connected. Remember, the more current you draw, the more work the regulator needs to do. The higher the input voltage differential from 5V is, the more work the regulator has to do. Minimise those two factors will minimise the heat the VREG generates.


Linear regulators are not efficient, and get worse when fed with higher voltage. Brett’s solution is the best answer, use an input voltage closer to the output voltage (5V) so the regulator doesn’t need to shed as much waste heat.

The other option is to feed the Domino with 5V directly, bypassing the onboard regulator. You could use a switching power supply to efficiently reduce the voltage from 12V.