My datamax thermal is not heating up - Datamax M-Class Thermal Printer

These printers do not "heat up" as such. Possible causes are:

1. Incorrect ribbon type for fitted ribbon spools. Look at back plate and see which way arrows are pointing. If arrows point Anti-clockwise, then you require inside wound ribbon (i.e. standard datamax) If pointing clockwise then you require outside wound (i.e. Zebra type ribbon). Check ribbons by touching sticky side of label to ribbon (it will transfer ink to label on print side).

2. Could also be faulty printhead, Logic board or Power supply. These will require an engineer to check properly.