FlashForge Creator Pro Extruder Heating when turning on.

[Leo_Threedprint]

I only have on extruder connected (not sure if this could be the problem). The other one is broken.

When I turn my printer on the extruder start heating up and wont stop till the machine shuts it self down. Any ideas?

Thank you.

[Fat_Ho]

Have you try to use PC to turn of manually?

[Key_3D]

Is it plugged into a Raspberry Pi running Octoprint or Astroprint? Something like that could override the settings. Alternatively I wonder if it’s set to preheat automatically for some reason? Have you navigated through the preheat options? You could try turning the extruders off. I take it the bed doesn’t heat up once the extruder has reached temperature?

[Mark_Walker]

The mosfet on the motherboard may have gotten zapped due to a short in the wire. They notoriously fail to the on position. You may be able to see the burned chip by looking at the motherboard.

[Perry_1]

STOP. Do not turn your printer on again until you have read this:

https://groups.google.com/forum/#!topic/flashforge/eMCJG-vX7o0

You could likely burn out your motherboard. Follow the instructions towards the end of the thread.

[3DNG]

I had the exact same problem, I know this is an old post but I want to leave a bit of advise to the people who might encounter this in the future.

Long story short I unwittingly shorted out the right heater cartridge and the mosfet burnt out. When I turned the machine on it started heating the right nozzle until it reached its limit and the printer turned itself off. When a mosfet on the board is letting current through you can see the corresponding led light up, most of the times when fets burn out they get stuck on the on position, so it lets the gate open for electricity to flow through and the led is always lit.

Repairing it was easy but you need to be patient and have a bit of soldering knowledge.

I got some FDS8812NZ fets since I couldn’t find the PSMN7R0-30YL or IRF1413 fets readily available in my country. I researched the different models and data on them. Don’t just go buy any model, do your research and it will pay off.

You will need:

1. Any of the mosfets listed above or any model close to them (N-Channel 30V 10A, SOF-8 or LFPAK are good)
2. Soldering iron with fine tip 25-50W models work fine.
3. Soldering wire
4. Desoldering wire/mesh
5. Liquid or gel Flux
6. Plenty of light
7. Magnifying glass

The process is simple, you need to de-solder the burnt one and solder the new one.

Watch this YouTube video to learn about Surface Mount Soldering onto circuit boards.

Attached are some pics I hope you find useful.