Can't upload to Arduino Mega2560, but Duemilanove is fine (Mac)

Hey, all!

I recently started a project and made some good headway with the Arduino Duemilanove until I ran out of pins. As a quick fix, I thought I'd switch over to the Mega to free up some more space for digital pins. I plugged all my jumpers into the Mega2560's ports and tried to upload, but I get the following verification error. I've truncated most of the beginning of the verbose output

avrdude: Recv: . [da] 
avrdude: Recv: . [1b] 
avrdude: Recv: . [dc] 
avrdude: Recv: . [1b] 
avrdude: Recv: . [00] 
avrdude: Recv: d [64] 
## | 100% 0.79s

avrdude: verifying ...
avrdude: verification error, first mismatch at byte 0x0000
         0x03 != 0x14
avrdude: verification error; content mismatch
avrdude: Send: . [1b] I [49] . [00] . [03] . [0e] . [11] . [01] . [01] N [4e] 
avrdude: Recv: . [1b] 
avrdude: Recv: I [49] 
avrdude: Recv: . [00] 
avrdude: Recv: . [02] 
avrdude: Recv: . [0e] 
avrdude: Recv: . [11] 
avrdude: Recv: . [00] 
avrdude: Recv: O [4f] 

avrdude done.  Thank you.

I've looked around and found some suggestions involving the bootloader, but really don't know how to proceed. Any suggestions would be superb.

Thanks in advance!

I found another Mega2560 laying around and tried hooking that one up. It works just fine! Does this indicate that there is something wrong with the bootloader other board?

ecopenhaver: I found another Mega2560 laying around and tried hooking that one up. It works just fine! Does this indicate that there is something wrong with the bootloader other board?

That or could be the USB serial converter chip. Next step is to run the loop-back test to see if the USB serial converter functions or not. There is a sticky around here somewhere on how to perform the test. If it passes then re-burning the bootloader on the 2560 chip would be the next step.

Lefty

I have the same problem: suddenly it became impossible to upload a new sketch to my Mega 2560: avrdude: verification error, first mismatch at byte 0x0000 Depending on the sketch, some byte being unequal to 0x14.

I did not try the loopback test, but the sketch that is in the Mega still gives serial output from a previous version, so I do not think that is the problem.

Re-burning the bootloader seems complicated and does not always work, judging from threads that I looked at. So I think I will waste some money instead of time and continue with another Mega.