Yesterday my arduino mega 2560 was working fine . Today i connected the 12V supply and then i connected the USB. Suddenly the PC switched off! After restarting i disconnected the supply then i connected the usb back, the arduino was not found. I tried different cables on different pc's, but still no success. I connected my friend's arduino nano, and it worked fine.
I noticed that the 3.3V regulator was very not, but with the help of the multimeter, i confirmed that the output is 3.3V. I also checked the +5V output pin with reference to grouns and to my surprise 8.38V was being outputed.
Can someone please advice any suggestions or solution?
Its the IC to the right of the socket. I have done some more testing and now the board is suppling 5V like it should but still its not workig with the Computer. My lecturer at school suggested that shince the board is recieving power but not data, the serial communication chip may blown. But is too smal for me to solder
Ok, if the USB/Serial chip is dead, you can bypass it.
Step 1- remove RN4, that will isolate the Rx Tx lines. Use a multimeter to determine if R4 is above the Rx/Tx LEDs, or below it. RN4 pins 1 & 2 connect to D0, D1 (or maybe D1, D0).
Step 2 - obtain a USB/Serial module, such as FTDI Basic
Step 3 - connect FTDI basic to the board, connecting Rx to Tx, Tx to Rx, DTR thru a 0.1uF cap to Reset, and Gnd to Gnd.
Install the FTDI drivers and program away.
If the 8V damaged the 16U2 on the board, there's a good chance the 2560 is damaged also too tho.
. Today i connected the 12V supply and then i connected the USB. Suddenly the PC switched off! After restarting i disconnected the supply then i connected the usb back, the arduino was not found. I tried different cables on different pc's, but still no success. I connected my friend's arduino nano, and it worked fine.
