Geeetech

Final update:
Used avrdude and the usbasp to upload ArduinoISP+bootloader hex to the arduino uno.
Then used avrdude and the arduino uno to program the usbasp with usbasp-v1.06-alpha-2016-05-18-atmega8.hex

Built b493 version of vert's firmware for A10. Merged that with the bootloader using srec_cat ...

Hmmm. So avrdude says the bootloader is written successfully. But Cura or firmware toolkit cannot upload firmware to the printer. After writing the bootloader, I read it out with this command:

"C:\Program Files (x86)\Arduino\hardware\tools\avr\bin\avrdude.exe" -C "C:\Program Files (x86)\Arduino ...

I watched a couple of bootloader programming videos on youtube, using Arduino Uno as programmer. In those videos, the printer board ICSP wires do not connect to the Reset pin on the Uno ICSP connector, they connect to pin 10 on the Uno, which is SS (Slave Select).

In my GT2560 wiring, I wired to ...

I tried two USB different ports on a laptop that has only 2 ports. Both ports work with usbasp and everything else USB I have used. If I can, I will move the printer near to a desktop PC and try the desktop USB ports.

That driver is what I had originally, and reinstalled. It shows as "USB-SERIAL CH340 (COM4)" in Device Manager (Windows 10 64 bit, all updates). I also tried a different usb port, the Device Manager showed the same except it registered on COM3.

So no progress. Bootloader installs successfully, but ...

Cura 4.5 does not seem to have option to select port. Either it detects the printer or it doesn't. It doesn't.

I tried the Firmware Toolkit main.exe. It autodetects the printer port (com 3) with message "Connecting remote end successfully!". I Select the firmware. Click on "Upgrade from local" and ...

That's the driver I have already. I did reinstall, no difference.

https://www.dropbox.com/s/i31rexe8dzknd ... r.jpg?dl=0

A10 with GT2560 Rev 3. Connected up a usbasp to the LCD board. Ran Arduino 1.8.12, set Tools to ATMEGA2560 and programmer to usbasp. Ran Burn Bootloader, apparently successful (see console messages below). Disconnect usbasp, power cycle the A10. Connect its USB to my PC, and unable to upload ...