New problem. At last i got my Mendel90 to work.

New problem. At last i got my Mendel90 to work. I had a test print of the frog yesterday, all went nice. But when i should start a new print today i have notice when bed starting to warm up it stop heat after about 4 sec and then i can’t get any warm back on ether the Hotend and Bed. The axis goes as normal. I haven’t done any changes sens yesterday.

Perhaps an alarm has been triggered. Could you try M562 and see if that does anything with the heaters? You could also check the terminal log for any alarm info.

Ok will check it tomorrow

When i try to set heat on the bed it goes 1 sec and power is cut to the bed and temp falls to 0 for 4sec and the same happening when i use the M562 command and terminal log says this “Send: M105
Recv: ok T:20 T1:0 T0:20 B:21 @:255.0
Recv: Alarm: Temperature falling too quickly (-21.4333) for HBP”

What would make the temperature fall that quickly for the heat bed? Are you sure the thermistor is OK on the heat bed?

Yes it seams so. When I put my finger on the termistor it goes to rock bottom. :frowning:

If the temperature falls quickly when you touch the thermistor, it sounds like you might have a broken wire, or am I misunderstanding you?

Yes. I have found the problem. Thanks for the tips.

@Jan_M_Simonsen - I have the same printer, any chance you could pass on your config please, would save me repeating your efforts.

My mendel90 config file

Just an aside @Jan_M_Simonsen - Your z steps/mm is just 25. I have a Mendel90 and the z-axis is directly driving a 1mm M6 threaded rod, so for me its 200 steps/mm. Just curious how your Mendel90 is so different to mine?

i use these for my z axis
http://www.ebay.com/itm/NEW-300mm-3D-Printer-8mm-Lead-Screw-Rod-Z-Axis-Linear-Rail-Bar-Nut-/331723399096?hash=item4d3c415fb8