HMS 0300-9100-0001-000A: chamber heater 1 abnormal, AC board suspect
LayerWalker is a participant in the Amazon Services LLC Associates Program. We may earn a commission when you buy through links on our site, at no extra cost to you.
HMS 0300-9100-0001-000A says the temperature of chamber heater 1 is abnormal and that the AC board may be broken. Two things follow. The fault is specific to one heater rather than to the chamber as a whole, and the suspect component sits on the mains side of the machine, which changes what you should and should not do about it.
Affected machines: X1 series and X2D. These machines drive their chamber heaters through an AC board, the same class of component that switches the bed. It lives behind its own cover for good reason and none of it is a user-replaceable part.
Where to buy
What you can establish safely
With the printer unplugged, you can check two things. First, that the chamber temperature sensor reads sensibly: around 100k ohm at room temperature. A sensor reading low makes the controller drive the heater harder than it should, which produces exactly this complaint from a heater that is fine.
Second, that the airflow path is clear. A heater with nothing carrying its heat away runs hot at the element while the chamber stays cold, and that also reads as an abnormal heater temperature.
If the sensor is healthy and the vents are clear, you have ruled out the cheap half. What remains is the AC board and the heater element itself, and at that point the correct move is a ticket rather than a screwdriver.
Chamber heating stops and the printer reports heater 1 temperature abnormal
Blocked airflow, a chamber sensor reading low, or a failed AC control board
- Unplug the printer at the wall. Do not work on this fault with the machine powered, even at the display.
- Wait several minutes before opening any panel so mains-side capacitors have time to discharge.
- Inspect the chamber heater vents with a torch and clear anything sitting against them.
- Measure the chamber sensor cold. Around 100k ohm is healthy; well below that and the controller is being misled.
- Confirm the heater fan spins freely and starts when the machine powers up.
- If the sensor and airflow are both sound, stop. Record the code and raise a support ticket rather than opening the AC board cover.
If the machine is out of warranty and the board is confirmed dead, price the repair before committing to it. An AC board plus labour on these machines lands uncomfortably close to the price of a current printer, which is what the last bar on the chart is for.
The over-temperature version is chamber heater over-temperature, and the bed-side equivalent is heatbed control abnormal. Our page on enclosed printers covers what the chamber is for, and the troubleshooting index covers the rest.
HMS 0300-9100-0001-000A FAQ
Can I print PLA with this code?
Yes. PLA does not use chamber heating. Anything needing a warm chamber should wait.
Is the AC board the same as the mainboard?
No. The mainboard runs the printer at low voltage; the AC board switches mains into the heaters.
What should the chamber sensor read?
Around 100k ohm at room temperature, falling as it warms.
Is it safe to open the AC board cover?
No. Leave that to service. Everything behind it is at mains potential.
LayerWalker
Print defect diagnosis, calibration procedures and parts that actually fit. Corrections welcome through the contact page.
