My Arduino works fine when its connected to the computer via the USB but as soon as I disconnect it from the computer, it goes off. I am using a 12V DC adapter (500mA) (center positive) as the external power source. Not sure what is wrong. Please help! Thanks!

Arduino stops working when connected to an external power supply

Topic		Replies	Views
Arduino UNO external power not working IDE 1.x	4	4256	May 5, 2021
Arduino external power supply issue IDE 1.x	2	516	May 5, 2021
How to Power Arduino Externally ? General Electronics	47	12565	May 6, 2021
power Troubleshooting	5	996	May 6, 2021
Check the external input power? General Electronics	8	1341	May 6, 2021