You need to match the baud rate.
do you know what baud rate the printer is set at? and the software?
These need to match, typically set at 250k baud.
--------------------------------------------------------
Custom all metal CoreXY
- Duet 2 Wifi w/ PanelDue 7i
- 330mm x 360mm x 500mm
- 750w Silicon heater
Custom Mendel90
(Backup printer - Old reliable!) - Sold