RAMPS 1.4 - Error during uploading Firmware (1 reply)

Hi,
I recently received a RAMPS 1.4 KIT from ebay. It's a Chinese Sainsmart kit.

The first thing I do after I opened the box was to mount the RAMPS on the Arduino 2560 rev3. After :
- I plugged the USB cable on the Arduino 2560
- I plugged it on my computer and install the driver (from arduino-0023 drivers file)
- in the Arduino 0023 software, I chose the Arduino Mega 2560 board and the good Serial Port (COM4)
- I oppened the Marlin.pde, change the configuration file (board #33)
- I launched the upload


The upload start and everything seems ok until the end of the upload and I have this message :

Binary sketch size: 48746 bytes (of a 258048 byte maximum)
avrdude: verification error, first mismatch at byte 0x1128
0xb1 != 0x31
avrdude: verification error; content mismatch


I don't have always the same bytes listed in the error message, it's strange..
I tried to remove the RAMPS for test only with the Arduino 2560, but it's the same problem.

Could you help me please ?

Regards,
Druss
Sorry if my english isn't very good...