i have this problem after burn bootoader
pleas help
led stay blinking 2 times
1- i cant upload any code (no tx rx blink)
2- i have this error messeg
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_getsync(): timeout communicating with programmer
Une erreur est survenue lors du transfert du croquis
Check the fundamental thing first, whether the port exists on the PC. No tx blink means that no call arrives to Arduino.
The L should blink 3 times fast at connection to PC or reset, it means also at uploading start. If no then try to upload the bootloader again. Make sure that used bootloader is correct.
all is good port and bootloader alll is good but the arduino is stay not working
Not all is good if the Arduino is not working. 
Tx should blink at least once as the upload starts.
I think this will not work.
i think is a hardwere probleme if i can upload code without using usb port with an other arduino uno ??
With other Arduino, via ISP or via RxTx? Post more detailed description.
If via ISP then the bootloader can be a problem. If via rx,tx then you would focus to on-board transceiver, i.e. ATmega16U2, its FW or the HW around it.
