Ring Pro doorbell isn't lighting up

I installed new Ring Pro doorbell and it kept blinking (incomplete circle) for hours till it was fully charged then it worked for few minutes then completely stopped. I upgraded the doorbell transformer from 5V to 16V/30VA but it's not working. At its best, it blinks incomplete circle (charging) for sometime and then lights never light again. I'm 100% sure that all connections are correct (since it worked for few minutes and when i plug in the old doorbell it works) but can't figure out why did it stop working !!