New Arduino Uno - Can't load code, "L" Led ALWAYS On

[babagharat]

Hi there everyone greetings!

I am newbie in using Arduino Uno. I am interested in home automation iot project so started with purchasing my first Arduino Uno board which unfortunately was not working.

When powered on it's L led remains lit. Pressing reset button nothing happens. Cannot upload sketch. When tried getting

avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x3e

Tested usb to serial communication loop back test ok.

Hence tried burning bootloader now getting

avrdude yikes! Invalid device signature 0x000000/0xff0000/0x0000ff/0xffffff error.

Suspected that Atmega328p chip may be faulty.

Got a new Atmega328p and burned bootloader in it on breadboard using another working Arduino and replaced it with the one on the faulty board. But same problem persist.

Also the original Atmega328p removed from the faulty board got the bootloader programmed using breadboard without any issues.

Hence I concluded that there is a fault on my board and not on the chip.

Therefore I need your help on troubleshooting the faulty board. Even after replacing the another chip with bootloader on the faulty board the L led still remains lit on powered and does not blink after pressing reset button also cannot upload sketch.

Thanks in advance.

[LarryD]

Using a voltmeter, measure the 3V3 and 5V pins, what are these values ?

[gilshultz]

I give you credit for making this a learning experience, if it were me I would have just sent it back. Next time you post please mention what part you have, a "Arduino UNO" only narrows it down to several different boards, not all with the same processor.

[babagharat]

Thanks for the quick response I measured the voltages and are 3.24 and 5.06
I had failed to mention that during flashing bootloader on the faulty board, when connected to programmer board the L led would switch off and then blink along with the L led on programmer board when blink sketch was uploaded to programmer board.

[babagharat]

The Arduino Uno board is ATMEGA 328p compatible board with MEGA 16u2 isp.

[babagharat]

Greetings!!!

Found the problem was on the board. The resonator was not working. Hence connected 16MHz crystal to pin 9 and 10 with respective 22 pf capacitor from back side of pcb and it's working like a charm.