reset

Hi friends, I am new on this ARDUINO fanstic word
the question is, how yoy can restart ARDUINO maga2560 r3 like of factory?
the problem is: the problem that the system does not accept any type of new program, moreover it has remained the last program that continues to run perfectly.
I tried to uninstall the software and reinstall it but nothing to do.
I'm really starting out, please help me with beginner's words.
thanks to all and congratulations for the preparation you have, I hope to become like you soon.
italiano:
il problema che il sistema non accetta nessun tipo di nuovo programma, inoltre è rimasto l'ultimo programma che continua a girare perfetamente.
Ho provato a disinstallare il software e reinstallarlo ma nulla da fare.
Sono veramente agli inizi, per favore aiutatempi con parole da principiante.
grazie a tutti e complimenti per la preparazione che avete, spero di diventare presto come voi.

If it would help, there is an Italian section here

So it used to work, and now no longer accepts uploads? That's a bad sign.

On a Leo/Micro, a bad sketch can break uploads. On an Uno/Nano/ProMini/Mega, it cannot. On those boards, there is no way to break uploading without either using an external ISP programmer, or damaging the hardware.

So:

Does the port appear when you plug it in?

If the port does not appear, do you get a new hardware detected sound/message when you plug it in, or nothing?

If you get no port, but the computer reacts when you plug it in, it's likely a driver problem.

If you get no port, and computer does not react when you plug it in, its a hardware problem. Try a different cable (There are a lot of bad USB cables floating around) or different USB port. It is fairly easy to damage the USB-serial adapter on official Arduino Mega/Uno.

If you do get a port, but upload fails, post the error message here.

Hi DrDazy
many thanks for your fast replay, I need many time to tray all your questions, I will answer you on next days.
Thank You

Hi DrDazi
here I am
I have make the test with cable, cable is ok I have changed with another one
the door in number 8
all the LEDs remain lit after I try to load a sketch (us per picture attached)
the error is:

Arduino:1.8.9 (Windows 10), Scheda:"Arduino/Genuino Uno"

Lo sketch usa 950 byte (2%) dello spazio disponibile per i programmi. Il massimo è 32256 byte.
Le variabili globali usano 9 byte (0%) di memoria dinamica, lasciando altri 2039 byte liberi per le variabili locali. Il massimo è 2048 byte.
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x00
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x00
avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x00
avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x00
avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0x00
avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0x00
avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0x00
avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0x00
avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x00
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x00
Errore durante il caricamento dello sketch

I hope I have given you all the information, in the meantime I have done other tests without any positive results.
Best regards
Marcello

You have uno selected as the board type while trying to upload to a mega..

Thank you very much, you were right
I have changed the board select and now it running very well
you are geniuses ... congratulations