i recently got into .... an undesirable fault with my Arduino Uno R3.........that is .....my Arduino does not turn ON ........when i use an external battery or any other power source to run my project............consistently ......a 3S1P fully charged Lipo battery.........it is a certain mishap i believe..........previously i did many tinkering with my project with this battery.......there was no problem until today...........with usb my project works fine .......but with a battery it doesn't..........when i remove all my connections......and then connect the battery........the onboard LED turns ON but in a very feeble manner...........i have checked 5v and 3.3v ...........both of them shows 2v ....voltage reading in a multimeter..........i even connected my battery with another arduino to check if its alright.........but yeah it works fine with the other one........which proves that it is a hardware problem.....plz help.......
NOTE:- i am a noob....... literally speaking
Sounds like the voltage regulator (or the components attached to it) have been damaged. Did you try to run a heavy load from the Arduino's 5V pin at some point in the past? Check for cracked and blackened components on the board, might be an indicator.
this .....makes........it very..........difficult.......to read........why..........are you using..........it?
i have checked the voltage regulator.........the Vin shows 9.8v even though i am feeding 12.3v from my Lipo...........and the Vout shows 2.02 v............what do you think now..........yeah may be........i power two servos with the 5v onboard feed........is it too much?..........i mentioned that .everything was working just fine......previously........my servos..were working just fine
Sagnik:
...i power two servos with the 5v onboard feed........is it too much?.....
Yes, 2 servos is too much amperage. I think your regulator is toast.
what voltage regulator should i buy to replace it
Arduino schematics are open source: http://arduino.cc/en/uploads/Main/Arduino_Uno_Rev3-schematic.pdf
Looks like an NCP1117 http://www.onsemi.com/pub_link/Collateral/NCP1117-D.PDF