Uno Fried?

Using Arduino IDE 1.x
1

Hi all,

Up until an hour ago my Uno was working fine.
After changing some wires around it stopped working (most probably I've damaged it).

Now it does the following:

  1. 5v output pin supplies 3.95v when Uno powered from USB and 1.4v when Uno powered from 12v battery.

  2. Green power light is ON. But Orange pin 13 led is off and doesnt blink twice when powering Uno up.

  3. TX / RX ports do nothing, even though the program currently on Uno utilises serial comms.

  4. Computer cannot communicate with Uno. I simply get "Board at COM3 is unavailable".

  5. The reset button on the Uno does nothing.

I'm not trying to figure out what caused it to break, just if my Uno is now scrap or not?

Thanks,
Jim

2

From the first observation I'd guess the 5V regulator has given up on life. If that's the case, it's a bit difficult to say if something else bought it too. You need proper power for proper function, after all.

3

Probably the regulator, but there are other parts it could be within the power supply section, you'd need some work with a DMM to figure out what exactly.

Is anything getting hot? If so, that's the bad part :wink: There's a little SOIC-8 package (with an opamp in it) that often fails to a near-short if power is reversed.

4

Yeah the reg was my first thought. Although the Mega chip is getting VERY hot.
Either was i'll get another ordered.

Cheers guys,
Jim

5

The regulator is probably fried.