Err: Mintemp Bed on MK2S
So i built the printer about a week ago now and it have been working flawlessly but i did mess up the height of the pinda probe so yesterday i decided to fix that and put the printer on a more level surface so i disconnected the printer and moved it to the other desk. Did the calibration starting with the preflight check under the assembly instructions and all the way too the first layer calibration print, preheated the printer for PLA and started the print.
However during the z calibration that runs before every print the target temp for both the heatbed and the hotend goes to 0 and the red light at the end of the heatbed turns off this seems to happen at a rather consistent point pretty much always at point number 4. The z calibration will finish and the printer returns to home and shows the error.
here is a video that shows whats happens on the lcd with the room temp measured with a multimeter at ~23C
I have checked the connections on the rambo board and as far as I can tell the cables dont go further in their connectors and the connectors are as much pushed down onto the board as they possibly can be. When i probe each cable with a multimeter i get the following resistance
heatbed 104.5kOhm
hotend: 99.5kOhm
now I'm not a genius with a multimeter i mostly use it for continuity and resistans in resistors (i always forget how to read the lines) so i might have measured wrong.
this is as far as i get for some reason the heatbed seems to shut down/trow the error but i cant figure out why. Also there is no plowing at the printer more than the two stock fans at the hotend.
any ideas on what to do next?
[Edit]
Actually i just noticed that regardless of the bed being heated or not i get the error when i move the y axis from the settings menu as well
the error is thrown once the extruder is between the 55 and 105 lines on the heatbed. If i continue to move the y axis and then reset the printer i get the error at start up if i move back to home it starts as it should but fails later as previously described
So when i measure the beads thermistor with the multimeter at that point i get O.L (same if beyond that point)
Re: Err: Mintemp Bed on MK2S
so you've already found the problem: a broken thermistor cable, with a slack joint.
maybe you've squeezed the cable during assembly at the edge of a zip tie ?
the whole cable trunk is one of the weakest points at the prusa i3 mk2 (even with "s").
you need to take care that you don't stress one of the wires while binding them together. at the other hand the whole cable trunk needs to be stiff (that's why it's enforced by the 3mm nylon filament), so that continuous movement doesn't bend any of the wires harmful.
depending on your skills, it's most likely that you've to replace the wires for the thermistor or even the whole thermistor (with attached wires).
dem inscheniör is' nix zu schwör...
Re: Err: Mintemp Bed on MK2S
yeah i just found which one of them went bad too. Actually the wire seems to have been damage by getting in between the spirals of the spiral wraps 2-3 cm from the ziptie at the bed. if the cable is loose i can move the bed freely whitout the error although the cable is damage so i'm contemplating maybe to just strip it a bit and get some heat shrink there. Dont know if thats a good idea yet though... anyway it would be until i can get a replacement for it.