If I power the Uno via USB the 5v pin reads 5v, as expected. If I power the board through Vin or the barrel adapter with 12v, the 5v pin reads 3.09v. If I power the board through Vin with 12v and USB, the 5v pin reads 4.5v. No other pins connected. Is there a way of fixing this board?

12v in 3.09v out Arduino Uno, fixable?

uglyfish April 6, 2018, 4:12pm 8

I've tested the power supply and it is OK, no AC reading, 12.31V DC. Will try to change the voltage regulator. Thanks all for the help.

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