HMS 0300-0200-0001-000B: right nozzle temperature control abnormal
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HMS 0300-0200-0001-000B means the printer has lost proper control of the right nozzle temperature. Note the wording: not that the heater is dead, and not that the sensor is open, but that the loop between them is no longer behaving. Either half can cause it, and they are told apart with a meter rather than by guessing.
Affected machines: H2C and the X1 series. On a machine with two nozzles, this code names the right one specifically, which is useful: the left half can keep working, and comparing the two sides is the fastest diagnosis available to you.
Where to buy
Use the good side as your reference
This is the advantage of a dual-nozzle machine. Measure the sensor on the right and on the left at the same room temperature; both should read close to the same figure, typically around 100k ohm cold. A right-hand sensor that reads wildly different from its twin is the fault.
Do the same with the heaters. Both should measure the same resistance. One that reads noticeably higher has degraded and will deliver less power, which produces exactly the wandering, overshooting control this code describes.
If both halves match and the code persists, the problem is the control circuit on the board rather than the hotend. That is a service item, and fitting a new hotend will not clear it.
Right nozzle temperature wanders, overshoots or fails to hold, and the printer reports abnormal control
Failing heater cartridge, drifting temperature sensor, or a poor connection at the toolhead
- Power off at the wall and let both hotends cool to room temperature.
- Unplug the right hotend at the toolhead and inspect the connector for a bent or recessed pin.
- Measure the temperature sensor on the right, then the left, and compare the two readings.
- Measure both heaters the same way and compare their resistance.
- Reseat the connector and retry a heat-up, watching whether the temperature holds steady at target or hunts around it.
- If the right side measures differently from the left on either part, fit a replacement hotend for your model.
Match the part to the machine. The X1 series and the P2S and H2 families use different hotend assemblies, and the listings look similar enough that ordering the wrong one is easy.
The related right-nozzle faults are right nozzle control fault or hotend not fitted and hotend temperature sensor fault. Our page on the hotend covers the assembly, and the troubleshooting index covers the rest.
HMS 0300-0200-0001-000B FAQ
Can I print with the left nozzle only?
For single-material prints that use the left tool, usually yes. Anything that switches nozzles will stop.
What should the sensor read cold?
Around 100k ohm on these machines. The important thing is that it matches the other side.
Is this the same as the hotend not being installed?
No. That has its own code. This one means a hotend is present and not behaving.
Could it be the connector rather than the hotend?
Yes, and it is worth reseating before you order. A partially seated pin produces a control fault that comes and goes.
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