random reset

Using Arduino IDE 1.x
1

Hello

I am new in this forum, and i use arduino a few months.

Recently my arduino duemilanove (328P) has some strange problem, no matter which sketch i upload to the board, when the sketch is running arduino do a random reset every few seconds . when it do a random reset the built-in L LED (which is connected to pin 13) blink.
can it happen because some problem with a bootloader or it's a hardware problem....?

Thanks for ahead

2

If it happens regardless of what sketch you have loaded it's probably a hardware problem.

Try installing a jumper between the Reset pin and the +5V pin. That should prevent the hardware reset signal from occurring. If that prevents the problem there is probably a fault in the reset circuitry. Use Google to find the schematic.

Check the pull-up resistor that connects Reset to +5v.

3

In addition to all of the other missing information, there is a troubleshooting step to try: use an external power supply instead of USB.

It is common for a background process on the host computer to poll serial ports, which will cause a reset. Cellular Data devices are typically the culprit in that case.