Hello guys,
I'm experiencing a very weird issue that is at this point beyond my capabilities to debug. For a while i had some issues with the print bed turning off in the middle of a print due to mosfet overheating i thought, so i added a fan at the RAMPS 1.4 and everything went ok for a couple of weeks. Today it happened again, so i decided to replace the Ramps 1.4 board.
After rewiring the RAMPS, just the heatbed at D8, and the two thermistors T0 and T1, i went to Pronterface and set the heated bed ON. It went on allright, but it never came off, and now the D8 gives me 12v all the time and the corresponding Ramps LED stays on. I think the mosfet or some other element overheated in a few seconds cause there was that funny smell (lightly) and now it can no longer control whether it should cut off the D8 line.
The plot thickens, cause i replaced the heated bed too, just in case there was some shorting there, and i put in ANOTHER RAMPS 1.4. The problem went on again, BOOM, D8 stays on after my first attemp to turn the heatbed on.
This last time, first thing i tried was turning it on via Pronterface without the heated bed conected to D8 rails and it went on ok, and then i turned it off ok (LED went out). But as soon as i connected the heatedbed, it screwed up another RAMPS 1.4 for good again.
ANY HINTS? I'm loosing my mind.
Best Regards, Alan
I'm experiencing a very weird issue that is at this point beyond my capabilities to debug. For a while i had some issues with the print bed turning off in the middle of a print due to mosfet overheating i thought, so i added a fan at the RAMPS 1.4 and everything went ok for a couple of weeks. Today it happened again, so i decided to replace the Ramps 1.4 board.
After rewiring the RAMPS, just the heatbed at D8, and the two thermistors T0 and T1, i went to Pronterface and set the heated bed ON. It went on allright, but it never came off, and now the D8 gives me 12v all the time and the corresponding Ramps LED stays on. I think the mosfet or some other element overheated in a few seconds cause there was that funny smell (lightly) and now it can no longer control whether it should cut off the D8 line.
The plot thickens, cause i replaced the heated bed too, just in case there was some shorting there, and i put in ANOTHER RAMPS 1.4. The problem went on again, BOOM, D8 stays on after my first attemp to turn the heatbed on.
This last time, first thing i tried was turning it on via Pronterface without the heated bed conected to D8 rails and it went on ok, and then i turned it off ok (LED went out). But as soon as i connected the heatedbed, it screwed up another RAMPS 1.4 for good again.
ANY HINTS? I'm loosing my mind.
Best Regards, Alan