Heatbed not working Hi I have just finished my 3d printer and the heatbed will not heat up. I was wondering what I should do to try to fix it? When turn on the heatbed on the repetier it says the temperature that it is set but the heatbed doesn't heat up. It is registering a temperature from the thermistor. I have tried removing the fuse and replacing it with a wire and that did not do anything. I have a 20amp power supply to power the 11amp side of the ramps board, there is a separate 16 amp power supply for the other half of the ramps board. The heatbed is a mk2b PCB heatbed, I did a test of the resistance and it is 0.8ohms. I do not have the LED hooked up on the heatbed. I have tried everything I can think of. Thanks for your help Tanner https://reprap.org/forum/read.php?4,420074,420074#msg-420074 Thu, 05 Mar 2026 12:32:45 -0500 Phorum 5.2.23 https://reprap.org/forum/read.php?4,420074,424916#msg-424916 Re: Heatbed not working https://reprap.org/forum/read.php?4,420074,424916#msg-424916 I had a look on your configuration file. Setting MOTHERBOARD 33 and setting a heatbed thermistor type should be all you have to do in Marlin to enable heatbed.

You can try to set heat bead manually. In case you have no LCD connected to your printer you may send e.g. the Gcode "M190 S50" to your printer. This should turn on heatbed heating to 50°. I don't know Repetier, whether you can send codes manually. In case not, you can also use the "Tools / Serial Monitor" of the Arduino Software. It will open a terminal window, where you can send the code manually.
You must only confirm that you have choosen the correct baudrate in the Arduino Software.

If you had send the command, the LED 2 should turn on, showing that the bed output is turned on.

BR]]> my-home-fab Reprappers Mon, 27 Oct 2014 10:02:47 -0400 https://reprap.org/forum/read.php?4,420074,424040#msg-424040 Re: Heatbed not working https://reprap.org/forum/read.php?4,420074,424040#msg-424040
The extruder is heating fine and D10 is reading 12V when switched on, but the heatbed is not responding (D8 = 0V). Thermistor is reading 22C for the bed and resistance is 1.2ohm.

Is there a line somewhere that needs to be changed to enable D8?]]> rvanwaes Reprappers Fri, 24 Oct 2014 15:20:06 -0400 https://reprap.org/forum/read.php?4,420074,423413#msg-423413 Re: Heatbed not working https://reprap.org/forum/read.php?4,420074,423413#msg-423413 if you have a look on the RAMPS Schematic (see: RepRap WIKI - RAMPS Schematic) LED 2 should light up if heatbed is turned on.
The position on the RAMPS you can see here: RepRap WIKI - RAMPS LEDs

I've wrote also an instruction for Marlin on RAMPS, see here: Marlin on RAMPS 1.4. Maybe this helps you a little bit.

Best Regards
Peter]]> my-home-fab Reprappers Thu, 23 Oct 2014 07:07:34 -0400 https://reprap.org/forum/read.php?4,420074,422807#msg-422807 Re: Heatbed not working https://reprap.org/forum/read.php?4,420074,422807#msg-422807 Stick one meter probe on the 12v negative input (11A) screw and the other probe on D8+ (Do you see 12v?) If so, put the meter lead on D8- . If you see 12v there also, then the bed in not switched on in your host software, or, if it is on in the host then the Mosfet is not being switched on for some reason. If you see 0v on D8- then all is probably ok there and it may be the wiring to the bed. So, disconnect the wires from D8 and probe them with your meter - do you still see ~0.8 ohms?]]> waitaki Reprappers Wed, 22 Oct 2014 03:15:20 -0400 https://reprap.org/forum/read.php?4,420074,420491#msg-420491 Re: Heatbed not working https://reprap.org/forum/read.php?4,420074,420491#msg-420491 Also how long should it take for the heatbed to heat up, maybe I am not waiting long enough.
Thanks
Tanner]]> tanner331 Reprappers Thu, 16 Oct 2014 18:40:33 -0400 https://reprap.org/forum/read.php?4,420074,420446#msg-420446 Re: Heatbed not working https://reprap.org/forum/read.php?4,420074,420446#msg-420446 Anonymous User Reprappers Thu, 16 Oct 2014 17:09:19 -0400 https://reprap.org/forum/read.php?4,420074,420364#msg-420364 Re: Heatbed not working https://reprap.org/forum/read.php?4,420074,420364#msg-420364
Quote
tanner331
Would it be in the Repetier software settings or the marlin firmware? Where is the spot to enable the heatbed?
thanks
Tanner

It would be in the Firmware and I am not to familiar with Marlin but looking at a config.h file for marlin I see the following.



I have Highlighted the line I think may be the one that Matters.

Doug
]]> dougal1957 Reprappers Thu, 16 Oct 2014 13:53:31 -0400 https://reprap.org/forum/read.php?4,420074,420299#msg-420299 Re: Heatbed not working https://reprap.org/forum/read.php?4,420074,420299#msg-420299 thanks
Tanner]]> tanner331 Reprappers Thu, 16 Oct 2014 11:05:45 -0400 https://reprap.org/forum/read.php?4,420074,420145#msg-420145 Re: Heatbed not working https://reprap.org/forum/read.php?4,420074,420145#msg-420145
Quote
tanner331
Hi
I have just finished my 3d printer and the heatbed will not heat up. I was wondering what I should do to try to fix it?
When turn on the heatbed on the repetier it says the temperature that it is set but the heatbed doesn't heat up.
It is registering a temperature from the thermistor.
I have tried removing the fuse and replacing it with a wire and that did not do anything.
I have a 20amp power supply to power the 11amp side of the ramps board, there is a separate 16 amp power supply for the other half of the ramps board.
The heatbed is a mk2b PCB heatbed, I did a test of the resistance and it is 0.8ohms.
I do not have the LED hooked up on the heatbed.
I have tried everything I can think of.
Thanks for your help
Tanner

Is the Heatbed enabled in the firmware Repetier by default has it disabled (I Know cos I had the same issues and took a while to figure it out).

HTH

Doug]]> dougal1957 Reprappers Thu, 16 Oct 2014 05:24:17 -0400 https://reprap.org/forum/read.php?4,420074,420074#msg-420074 Heatbed not working https://reprap.org/forum/read.php?4,420074,420074#msg-420074 I have just finished my 3d printer and the heatbed will not heat up. I was wondering what I should do to try to fix it?
When turn on the heatbed on the repetier it says the temperature that it is set but the heatbed doesn't heat up.
It is registering a temperature from the thermistor.
I have tried removing the fuse and replacing it with a wire and that did not do anything.
I have a 20amp power supply to power the 11amp side of the ramps board, there is a separate 16 amp power supply for the other half of the ramps board.
The heatbed is a mk2b PCB heatbed, I did a test of the resistance and it is 0.8ohms.
I do not have the LED hooked up on the heatbed.
I have tried everything I can think of.
Thanks for your help
Tanner]]> tanner331 Reprappers Thu, 16 Oct 2014 02:13:12 -0400