Extruder Overheating without Command

[losgood]

Another extruder problem here...

One of my extruders starts to heat up when I turn on my 3D printer without me commanding it to do so, and the heating won't stop no matter what I do. Even when the error: MAXTEMP came up, the heater continued to heat the extruder and I had to unplug the printer to get it to stop.

The extruder was working fine a couple of days ago and the thermistor also seems to be working fine so I'm pretty confused. Is it just a bad extruder or heater? Or is there anything on the control board that I can check?

[William]

Another extruder problem here...

One of my extruders starts to heat up when I turn on my 3D printer without me commanding it to do so, and the heating won't stop no matter what I do. Even when the error: MAXTEMP came up, the heater continued to heat the extruder and I had to unplug the printer to get it to stop.

The extruder was working fine a couple of days ago and the thermistor also seems to be working fine so I'm pretty confused. Is it just a bad extruder or heater? Or is there anything on the control board that I can check?

Hi,
You said the extruder worked fine before,so i think you'd better have a check to the relevant cucruit by referring this：
http://www.geeetech.com/forum/viewtopic ... 23&t=17030
Good Luck

[losgood]

That article is helpful, but I don't think it solves my problem. When the extruder overheats the MAXTEMP error turns on when its supposed to.

My problem is that the extruder uncontrollably heats up until the 3d printer is unplugged. Even when the temperature on the extruder is set to 0 it still will start heating up...

[William]

That article is helpful, but I don't think it solves my problem. When the extruder overheats the MAXTEMP error turns on when its supposed to.

My problem is that the extruder uncontrollably heats up until the 3d printer is unplugged. Even when the temperature on the extruder is set to 0 it still will start heating up...

Try to re-upload the corresponding firmware again,attach a video plz if it doesn't work yet.
Regards

[losgood]

Well, I re-uploaded the firmware but now I can't even take a video or test out my printer because of another problem, my printer has just about stopped working all together.

I think there is something wrong with the power or the control board. I've checked all the power connections multiple times and I looked over the control board to see if anything had burned or if something looked awry but found nothing. I'm even more confused now because it was working fine yesterday and now nothing will work (fans, motors, extruder heaters) except a few lights. Also, when I plug into my computer and connect to Repetier, I can heat the print bed with the power from my computer and the LCD display faintly turns on. This is just utterly frustrating.

Do you have any suggestions William Kwok? I really appreciate your help.

[William]

Well, I re-uploaded the firmware but now I can't even take a video or test out my printer because of another problem, my printer has just about stopped working all together.

I think there is something wrong with the power or the control board. I've checked all the power connections multiple times and I looked over the control board to see if anything had burned or if something looked awry but found nothing. I'm even more confused now because it was working fine yesterday and now nothing will work (fans, motors, extruder heaters) except a few lights. Also, when I plug into my computer and connect to Repetier, I can heat the print bed with the power from my computer and the LCD display faintly turns on. This is just utterly frustrating.

Do you have any suggestions William Kwok? I really appreciate your help.

OK,it just sounds like you didn't turn on the power of your printer,you know,i'm not sure about that...And are you sure you have reload the firmware successfully?Cuz generally speaking,it doesn't broken itself if you don't make some modification to the circuit on the motherboard.Did you do that?
Waiting for your reply.

[losgood]

I'm pretty sure the firmware uploaded correctly because the arduino window on my computer said "done uploading" with no errors being shown.

I haven't made any modifications to my control board besides plugging and unplugging wires on the board to organize the wires and prevent tangles.

I'm also positive I had the power on when I was trying to operate my 3D printer, it just won't operate.

I'm open to suggestions of what I can do to try to fix this though.

[William]

I'm pretty sure the firmware uploaded correctly because the arduino window on my computer said "done uploading" with no errors being shown.

I haven't made any modifications to my control board besides plugging and unplugging wires on the board to organize the wires and prevent tangles.

I'm also positive I had the power on when I was trying to operate my 3D printer, it just won't operate.

I'm open to suggestions of what I can do to try to fix this though.

Well,now check whether the DC output of your power is normal or not,cuz you said nothing works now.
Additionally,extruder heats up uncontrollably，it also can be the mosfet's problem,cuz it is the mosfet that controls the extruder to heat up.So check the mosfet like this as the pic below shows:manually heat up the hotbed and extruders, if the LED lights under the hotbed and extruder slots all lighted up, then the mosfet that controls the heating is good.

123.png (312.22 KiB) Viewed 14735 times

If not, the mosfet might be dead.

[losgood]

Thanks for the reply William Kwok, I still can't even get my 3D printer to turn on.

Do you think it could be because my Power Supply Unit is out of specification? The label on the PSU posted on the geeetech website says "OUTPUT +12V 20A" while my PSU says "OUTPUT" +12V 21A". See the difference below.

My PSU:

PSU2.JPG (12.97 KiB) Viewed 14706 times

Geeetech PSU:

PSU1.JPG (11.64 KiB) Viewed 14706 times

I feel like 1 amp isn't a huge difference, but its enough to stop my printer from working isn't it?

[Toy]

The current is just a rated current, I don't think it's the PSU problem.
Not stop heating might because the mosfet for extruder doesn't work, maybe it's not soldered well.
You need also check the voltage input, the fuse, see if there's anything wrong.
http://www.geeetech.com/forum/viewtopic ... 19&t=17039