led blink

hi, what does it means when i plug my arduino mega 2560 on my pc the led 13 blink continuously? and i cant upload my codes? it only says uploading but it takes a long time … thank you…

Some models of Arduino Mega will freeze up if your sketch contains three '!' characters isn a row. Check for that.

your Mega blinks continuously because by default, it contains the blink sketch. What OS are you using? if it is a windows, probably you have to install drivers, if it is a mac, select the right port. Another possible reason which i come to learn is that try and use a different cable, it helps. cheers