RESOLVED avrdude: verification error

Compile of Marlin software for my 3D printer succeeds okay, but the upload fails with the following error:

Sketch uses 200738 bytes (79%) of program storage space. Maximum is 253952 bytes.
Global variables use 4737 bytes (57%) of dynamic memory, leaving 3455 bytes for local variables. Maximum is 8192 bytes.
avrdude: verification error, first mismatch at byte 0x0000
0x14 != 0x0c
avrdude: verification error; content mismatch
avrdude: verification error; content mismatch

I have tried 2 different 3D printers and 2 different USB cables.

Arduino 1.8.4 and Windows 10.

Thoughts?

Turn on verbose output during upload in the preferences and post the output you get then.

With verbose upload on, this is the result:

avrdude: Version 6.3-20171130
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2014 Joerg Wunsch

System wide configuration file is "C:\Users\Mike\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino14/etc/avrdude.conf"

Using Port : COM4
Using Programmer : wiring
Overriding Baud Rate : 115200
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_getsync(): timeout communicating with programmer

avrdude done. Thank you.

An error occurred while uploading the sketch

That output suggests that your Arduino is not connected to COM4 or doesn't have a bootloader installed. Is your printer using a standard Arduino Mega2560? Is it intended to be updated over the USB interface?

Holy mackerel... These 3D printers do not have an Arduino Mega2560. They have a single custom PCB that appears to be intended to combine the Mega2560 functionality with the Ramps functionality.

They are supposed to be able to update via the USB, but obviously, there is something different about them.

These are ADIMLAB Gantry Printers

Hmmmm... Maybe it needs a different baud rate. Is it possible to change the baud rate when uploading with Arduino?

Where did you find the information that the board they use is compatible with the Mega2560? I found a reference where they say it's a 32bit board (the Mega2560 is an 8bit board).

pylon, I don't remember where, but there was a reference to uploading new firmware to the board via usb, so I can't address your specific question. I thought that meant it was emulating the 2560.

This problem is now resolved.

I have disconnected the original controller, and am about 3/4 done connecting a Genuine Arduino Mega2560 and a Ramps 1.4 to the printer. Will do the same to the other when I have enough parts.