extruders and htbed not heating

I just built a German RepRap V3 (dual extruder + heatbed). Initially all worked fine (including extruders and heatbed) except the x-axis did not move (engine just turned 1/8 turn clockwise, then same anticlockwise creating a "shake"). Turned out I could not get neither the engine to run on another driver nor the driver to run another engine.so I took the engine and driver from the second extruder, X-axis now works fine.

However, after the swap, the heatbed and none of the extruders can heat, temp readings are 21 deg C which is correct. In repitier host, heatbed shows on, when I start it from manual control, but does not heat, the extruders turns of after a second or so. What could be wrong? Did I fry my RAMPS (I unplugged everything before connecting/disconnecting everything)? It is unlikely that all MOSFETS broke?!? Or my ARDUINO Mega died? How can I measure to exclude one or the other?

I have 11V between ground and both legs of both fuses (this board has no resetable fuses but one 5 Amp and one 10 Amp melt fuses, same type as I have in my car), suggesting these are fine. What else can I measure? Or is the software (repitier host or firmware) somehow recognizing I took one of the extruders away and refuses to cooperate because of that? I did set one extruder in the repitier host settings panel, but did not recompile the firmware ...

All help highly appreciated!

/

The host does not have anyway to measure if a signal is passing through a stepper driver to a motor or if components are changed in this instance. It also is very unlikely that all MOSFETs were fried in one go.

First thing to do would be to unplug the stepper driver from X axis. If the heaters begin to work fine once again then it is related to the driver/driver socket. Check to make sure there are no bridged pins underneath the Ramps board. If the heaters work again then you will need to check for solder bridging, remove them, and try again.

If the problem still is present and no pins are incorrectly soldered than you may need to give a new ramps board a try.

---

Prusa i3 Rework - Ramps 1.4 - E3d Lite6 - Full Graphic LCD Controller

Thank you for the reply. I just solve the problem. German RepRap has several variants of that firmware here:

[wiki.germanreprap.com]

I downloaded the one for one extruder, heated bed and LCD, now the bed and the extruder works perfectly fine. My take is that somehow the original firmware (the one for two extruders, heated bed and LCD) did not like that one of the extruders were removed. I did not think of this originally, but it seems kind of logic given that there are several versions, although I really don't get it. I don't know how different the RepRap firmware are from the standard RepRap firmware (I don't think much?).

I this not what would be expected from the standard firmware? I wonder why the program logic is like this, why would the heated bed be dependent on the extruder? And one extruder on the other? I could understand if the printing would not start due to one extruder not reaching temp (unless its disabled) but preventing the other from heating is od. If I understand correctly, they are heated through different circuits in the RAMPs ..

Or everything magically solved itself over night (I did not test the printer before switching firmware)?

All good, time to make a print!

/

Take a look at Thomas Sanladerer's youtube page. He has a video on basic firmware configuration you can use to set the correct values for your printer.

---

Prusa i3 Rework - Ramps 1.4 - E3d Lite6 - Full Graphic LCD Controller