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

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

Would it be in the Repetier software settings or the marlin firmware? Where is the spot to enable the heatbed?
thanks
Tanner

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

You definitely need to define the thermistor type for the heat bed, as @dougal1957 says, but you also need to specify the correct board type. For example, Marlin has a setting for RAMPS with a single hotend, heated bed and fan or dual hot ends, fan and no heated bed.

I have a thermistor set for the heatbed, thermistor 1. And I have selected the correct board , 33, with a extruder, a fan, and a heatbed. What else should I check for the heatbed?
Also how long should it take for the heatbed to heat up, maybe I am not waiting long enough.
Thanks
Tanner

Try a continuity test....
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?

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Waitaki 3D Printer

Hi,
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

Edited 2 time(s). Last edit at 10/23/2014 07:09AM by my-home-fab.

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RepRap Electronics, Mechanics, NEMA 17, Filament you find here: [www.my-home-fab.de]

I'm having the same problem and can't seem to find any settings in Repetier-Host or Marlin that should be disabling it. Attached is my Configuration.h

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?

Hi,
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

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RepRap Electronics, Mechanics, NEMA 17, Filament you find here: [www.my-home-fab.de]