[SOLVED - Freaking low bat in Multimeter] UNO Delivering 6.6V from 5V pin to GND

Other Hardware General Electronics
1

as the title says, my 5v pin is delivering 6.6v. Is this normal? I've only had this thing a week. Also the data pins are delivering the same when high.

2

If this is when connectet to USB only -> USB-port is defective.
If its with external power (DC 7V..15V) only ->voltage regulator is defective

if in both of above.. -> Your multimeter is 'far off'.

3

Well......

It was connected to my new macbook pro late 2013

I just tried it plugged into a 5V/2.5A adapter and now its reading 4.25V

wouldn't expect my usb port to be damaged....

4

That 5V adapter giving 4.24 is good. (the regulater drops nearly 1V)
If U could try above 7V (max 20) and then measure 5V -> then the USB is delivering those 6V (which is too high)

I dont promise that 6V will kill your arduino, but its outside operating condition (max 5.5V)
Running from 4.2V will work just fine in most setups.

If your MAC delivers 6V where it should be 5 - replace it

5

Crazy.... Thanks and I'm glad I asked..... You can imagine the results I got when I typed "Arduino 6v from 5v pin" into google lol. Hundreds of pages with 5v and 6v in bold but none pertaining to my question........

I just tried connected to the laptop again and it read 7V!!!!! I can't hook that up anymore until I check that out!

6

I can confirm, I just read 7.14V from the USB cable that came with my UNO connected to my MacBook.

Edit: Both ports (one on each side of the laptop) are reading the same, 7.14V.

Facepalm edit: battery was low in my multimeter......... 5.16V on all ports....... man I can be dumb sometimes.....