Hey jonesy1505,
The fact that the printer's displaying a temperature (and not an error) suggest the head thermistor is working. So, although your room thermostat registers 17 degrees, it's possible that's not the temperature in the printer chassis (where the head is positioned).
To confirm the temperature in the print head area, power off the printer and place a small, digital thermostat in the printer chassis (near the head). Wait about 10 minutes and check the temperature.
If the digital thermostat reads -4 degrees, you've found your issue. The ambient temperature is just too cold. Raise the temperature at and around the printer and that should solve the issue.
However, if the digital thermostat reads the room temperature (you indicated 17 degrees), you and VanderJ are on the right track - possible failure of the head and/or the head trailing cables. It's also possible that the fun junction board or servo board are contributing factors, but we'll defer that assessment to the dealer that sold you the print head. They can handle all of this for you. Please call them ASAP to schedule service.
If you have additional questions or need extra support directly from Roland corporate support, please submit an "official" support request form online here:
Product Support Form | Roland
If you do write us, we look forward to helping you and take care,
Roland Technical Support
Roland DGA Corp.
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