avrdude: verification error; content mismatch

Hello, i have been working with my arduino uno and mega2560 for some time and had no issues, but today i came with a problem with my arduino UNO re-uploading an sketch that i successfully uploaded without problem few hours before, now i get an error no matter what sketch i try to upload:

avrdude: verification error, first mismatch at byte 0x0000
0x0c != 0x00
avrdude: verification error; content mismatch

it says upload finished and shows this error after,

the RX/TX leds blink like it was uploading, the led 13 blinks when i press reset and when i connect the power, i have also done a looback test and it passed it, i have also tried to upload the same sketch to my arduino mega2560 and it uploads and works fine, but on the uno doesnt.

when my uno worked fine i uploaded the sketch im working on, mount it on my robot, see how it worked, unplugged it, changed the sketch and then tried to upload but this time got me the error from above, now i have to work with my mega2560 (wich takes more space) on the robot, i dont know what else to do, any ideas why this happens and how to solve it? :frowning:

verbose attached

Oh, i have also tried to reflash the bootloader throught ISP with my mega2560 as programmer and my uno as target but i get this two error

avrdude: Expected signature for ATMEGA328P is 1E 95 0F
Double check chip, or use -F to override this check.

and

avrdude: Yikes! Invalid device signature.
Double check connections and try again, or use -F to override
this check.

verbose.txt (59.8 KB)

Not sure about the verify problem but the signature problem may mean you didn’t disable auto-reset on the MEGA after uploading the ArduinoISP sketch. If the MEGA gets reset you end up talking to the MEGA’s bootloader rather than the ArduinoISP sketch it was running. The signature of the MEGA is different from the UNO so avrdude gets a signature different from what it expects.

i dont know how to disable auto-reset, i have searched over the internet and found if i put a 100n cap on reset adn 5+ that will disable auto-reset, is that what you mean?

i have tried putting a cap(100n, 1u) between reset and ground and still shows same error

avrdude: Expected signature for ATMEGA328P is 1E 95 0F Double check chip, or use -F to override this check.

what else can i do?

well since no one helped that much, i tried buying another atmega328p chip to see if it was the chip and guess what, it was the chip that didnt work, just to let you all know