runamok

Thanks for the tips. I don't have the schematics, that would be a great reference if you can post a link.. Thanks!

The fan appears to be the culprit. If I disconnect it now, everything behaves nicely. The TC triple wire was crimped, but the fan cable appears to be something else.. it has shrink tube on the connections. I'm going to see if I can rework those. Thanks

Yep, I've tried swapping the two TC cables and had similar results.. They look crimped, and I checked the black-red-yellow cable with an ohm meter, and it seemed to have continuity on all 3 wires.. I checked potentials with my voltmeter relative to the USB plug case, and everything seemed nominal (0.02v or less) I tried a variety of spots on the print-head, the axes, etc.. I tried connecting the fan ground (black) to the printhead screws and that put the temperature at 383, which seemed a little high.. so I disconnected that.. I also tried reflowing a few of the connectors on the board (the TC, the heater, the fan) with my soldering iron. Didn't seem to change anything.. Are there any troubleshooting guides that can lead me through what voltages should be where, resistances, etc? Thanks

A bit more information.. I saw a comment from 'gr5' suggesting that the TC wire was very sensitive to other wires nearby (http://umforum.ultimaker.com/index.php?/topic/4680-ultimaker-original-not-working/?p=40437) So I routed the TC wires as far away from the fan and heater wires as I could This showed some improvement.. When I turned the power on, it now hovers around 15-18 degrees.. Enough where it won't immediately throw a MINTEMP error. BUT, if I touch the printer in any way (including the control knob on the ulticontroller) the temperature immediately drops to 0 and throws the MINTEMP error. As I was searching around for the reference to that post, I found another post about connecting the ground wire of the fan to the printhead.. http://umforum.ultimaker.com/index.php?/topic/4355-grounding-the-print-head-for-better-temperature-stability/ I'm not at home currently, but that sounds very promising. Clearly the print-head is floating around at some odd potential, and the wooden case doesn't provide much of a ground path.. I will try that tonight... Thx

Hi, I just recently got an Ultimaker Original. I'm getting an Err: MINTEMP error reported on the display. The temperature reading is either a very low number (less than 10) or 0. It tends to fluctuate a little around 6-8.. It seems to be some sort of grounding problem between the thermocouple and the heating element. If I remove either one from the hot block, the temperature becomes stable at 20deg. I have a dual extruder kit, and I've swapped the TC, the heating element and the TC amplifier board and got the same results. I've checked all the connections (a few times) and it all looks good. I've got the latest 15.02 firmware from Cura. Another odd behavior is that when I put my hand anywhere near the TC wires (or for that matter, anywhere near the top of the printer) the temperature reads around 20.. If I touch the bottom of the printer (on the wood), the temp goes to 0. Any tips would be great! Thanks!