Photon Mono M7 Pro: the resin vat does not heat the resin or code 307 appears
Guide based on the manufacturer's official documentation; usi3d has not yet verified it on a machine.
Technology: Resin · Brand: Anycubic · Symptoms: The printer shows an error code or message, Temperature error (MINTEMP, MAXTEMP, thermal runaway), The resin print does not stick to the build plate · Updated on 10 October 2026
Symptom
The Photon Mono M7 Pro reports «Heating abnormality, heating has ended (CODE: 307)» and stops heating the vat, or in a cold room the prints fail because the resin is not at its temperature.
Likely causes, from most to least likely
- 307: within the first 30 seconds of heating, the temperature sensor (NTC) reads 5 °C above the set temperature, or heating takes longer than the preset time.
- The vat temperature sensor fails, or the heater (PTC) keeps heating and makes the sensor fail.
- A wiring connector is loose or unplugged, especially the sensor connector in the vat heating module.
- Room below 20 °C without heating turned on: the resin flows less well and the print does not stick.
Checks to tell which one it is
- Note whether 307 appears within the first 30 seconds of heating (the sensor reads too high) or after heating for a long time (the time ran out).
- Check that your resin is not above 9000 cps viscosity: the heated vat heats for 25 minutes at most and supports resins up to that value.
- Check the room temperature: below 20 °C it is worth heating the vat.
Before you start
Uncured resin irritates skin and eyes: wear nitrile gloves and safety glasses, ventilate the room and do not look at the UV light. Before taking anything apart or cleaning it, switch the printer off and unplug it, unless a step says otherwise. If in any doubt, stop and ask a professional.
Step-by-step fix
Turn on vat heating
Below 20 °C, go to «Tools» → «Advanced» → «Intelligent Resin Vat Heating», choose the temperature and turn on automatic heating. The M7 Pro heats the resin to keep it at about 25 °C, its optimal temperature.
Check: The vat reaches the temperature without error and printing starts.
If that does not fix it: If 307 appears, check the sensor (next step).
Reconnect the heating module sensor (307)
Switch the printer off and unplug it. With the 2.5 mm Allen key remove the screws holding the housing of the vat heating module and, with the 2.0 mm key, the lower screws; remove the housing, unplug and reconnect the sensor (NTC) cable and put the housing back.
Check: When you heat the resin again, the error does not appear.
If that does not fix it: If it persists, replace the sensor cable (next step).
Replace the sensor cable
With the printer off and unplugged, replace the sensor (NTC) wiring with the 2.0 mm key and refit the module housing with the 2.0 and 2.5 mm keys.
Check: The resin heats without code 307.
If that does not fix it: Contact Anycubic support with a photo of the message and what you have tried.
If the print still does not stick with warm resin
With the vat at its temperature, check the exposure, the resin settings and the leveling as Anycubic describes for prints that do not stick to the build plate.
Check: The print forms on the build plate.
If that does not fix it: Contact Anycubic support.
Prevention
- After heating for a long time, the vat can be very hot in places: do not touch it directly when you finish.
- Use resins up to 9000 cps with vat heating.
- Pour the resin wearing gloves and a mask, without going above the vat's MAX line.
Still not fixed?
Tell usi3d's AI about your case: choose your printer, describe what you see and add photos if you like. It proposes checks step by step, with their sources.
Printers it applies to
Anycubic Photon Mono M7 Pro.
Official sources
This guide summarises the official documentation linked here:
This guide is general information: usi3d has summarised it from the official documentation linked here, and it may not match your model, its version or its firmware. If in doubt, follow the manual and the support of your printer's manufacturer. You decide what you do with your machine, and working on it may affect its warranty.