Fried atmega8u2 and probably the entire mega2560

Hello everyone. Here is my problem: arduino mega 2560 is not listed as a device, and cannot be programmed by USB nor ICSP. The led works (pattern: blin-blink-pause). Uploading a programm through ICSP seems to work but the program doesn't work and the led stays off.

How did this start? I uploaded a sketch that would read every pin status, analog, input and output. It fried TWO arduino mega2560. Both stopped working. For some strange reason one of them started working while I was trying to find what was wrong, even though I didn't fix anything, I just plugged it and it was alive again. But I have still one dead arduino mega, and I bought an AVR isp MK2 programmer to try to fix it.

Details on what I have tried: I have an AVR ISP MK2 programmer so I tried to burn the armega8u2 firmware through ICSP:

sudo avrdude -p at90usb82 -F -P usb -c avrispmkii -U flash:w:MEGA-dfu_and_usbserial_combined.hex -U lfuse:w:0xFF:m -U hfuse:w:0xD9:m -U efuse:w:0xF4:m -U lock:w:0x0F:m

avrdude: stk500v2_command(): command failed
avrdude: stk500v2_command(): command failed
avrdude: stk500v2_getparm(): failed to get parameter 0xa1
avrdude: stk500v2_program_enable(): cannot get connection statususe:w:0xD9:m -U eavrdude: initialization failed, rc=-1
avrdude: AVR device initialized and ready to accept instructions
avrdude: Device signature = 0x000000
avrdude: Yikes!  Invalid device signature.
avrdude: Expected signature for AT90USB82 is 1E 93 82
avrdude: NOTE: FLASH memory has been specified, an erase cycle will be performed
         To disable this feature, specify the -D option.

avrdude done.  Thank you.

mega8u2 seems to be fried.

Then I tried to burn the bootloader through the mega2560 ICSP port but the arduino IDE gives me an error trying to burn the bootloader, and the console log is empty.

So I tried to burn the bootloader manually:

sudo avrdude -c avrispmkII -p m2560 -P usb -U lock:w:0x3F:m -U efuse:w:0xFD:m -U hfuse:w:0xD8:m -U lfuse:w:0xFF:m
sudo avrdude -c avrispmkII -p m2560 -P usb -v -v -v -U flash:w:stk500boot_v2_mega2560.hex
sudo avrdude -c avrispmkII -p m2560 -P usb -U lock:w:0x0F:m -v -v -v

Every command works as expected. no error messages are shown. BUT the arduino is still not recognized. By now the led blinks twice, pauses, and keeps repeating this cycle.

As a final test I uploaded a sketch to the arduino using the ICSP port. No errors are shown, but the program NEVER starts. I'm talking about the simple "blink" example program. no modifications, I just load it, compile it and try to upload it using the programmer (Ctrl+Shift+U). This time the leds simply stops working until I burn the bootloader again.

Can you show us the sketch? Was anything else atached to the Arduino? Did you power it up via USB or DC adapter? Maybe you can't read digital outputs, I don't know i'm just guessing.

Regards

The sketch is long gone. It was just a test and I lost it. This happened months ago, but the programmer arrived last week.

There was a circuit connected to the arduino: a nRF24L01 wifi transmitter/receiver and a chinese remote control receiver. I thougth these guys were the cause of the entire problem, but I'm still using the same (literally the same) board with another arduino and everything is working fine. I double checked the fuse in the arduino board, and it's not used, it's working fine.

This seems to be a hard problem to solve, since I'm the only one with access to the real hardware, so here is another question:

How do you correctly remove the atmega8u2? I wan't to disconnect it from the arduino, because I suspect that it's causing a short circuit somewhere.

Thanks!

dc740: This seems to be a hard problem to solve, since I'm the only one with access to the real hardware, so here is another question:

How do you correctly remove the atmega8u2? I wan't to disconnect it from the arduino, because I suspect that it's causing a short circuit somewhere.

Thanks!

The correct question is, how do I remove a surface mount integrated circuit? There must be some instructions on google.

mart256:

dc740:
This seems to be a hard problem to solve, since I’m the only one with access to the real hardware, so here is another question:

How do you correctly remove the atmega8u2? I wan’t to disconnect it from the arduino, because I suspect that it’s causing a short circuit somewhere.

Thanks!

The correct question is, how do I remove a surface mount integrated circuit?
There must be some instructions on google.

Too bad, I thought I could just cut a few traces. I saw the tutorials, but I don’t have the tools to do it. I think I’ll just buy another one.

Thanks

Correct answer is use a hot air rework station to remove SMD parts.

I've been amazed at how easy it can be to remove SMD parts with a low-wattage iron and a few pointy tools, and even to clean up the resulting mess on the board.

Now, replacing with a new SMD part, that's well beyond my capabilities.

Unless you want to invest in the tools and practice up, your best bet is probably getting help from someone local with both tools and experience, or board replacement.

The time and effort that involves replacing and testing the new atmega8u2 is going to take you more than buying a new mega2560 I guess.

I agree:

http://m.banggood.com/Mega2560-R3-ATmega2560-16AU-Control-Board-With-USB-Cable-For-Arduino-p-73020.html

Mark it up to education.

And if you think education is expensive, try ignorance.