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New fan and thermistor aren't working
Posted: Mon Jan 08, 2018 7:19 pm
by norleck
Long story short, I scored a makergear M2 pre-2015 model with the Z motor mount broken off. I ordered a new motor mount and ran the M2 Quick Start guide. I leveled the bed and the bed heated fine. However it wasnt reading the printer head as heating up. After confirming the head was hot, I figured the thermistor was broken. I also noticed the upper fan wasn't working so I ordered a new thermistor and a new fan. I should have checked the voltage! The new fan or thermistor doesnt work. I have no voltage going to FAN 0 or HEAT 0 connection. I cant seem to find a wiring schematic to tell me where to start looking. I'm not sure what other info ya'll need from me but any help would be most appreciated!
Re: New fan and thermistor aren't working
Posted: Mon Jan 08, 2018 9:00 pm
by norleck
Follow up:
After checking it with the printer head heating up, I have voltage to HEAT 0 but I still can't get the thermister to read. HEAT 0 varies wildly between 9 and 14 volts. M2 Quick Start doesnt see the Heat Extruder as heating up but it is hot. Still no voltage to FAN 0.
Re: New fan and thermistor aren't working
Posted: Mon Jan 08, 2018 9:23 pm
by insta
You're not likely to get a good voltage reading at the leads, because they are switched-ground MOSFET outputs.
What is the actual thermistor reading you're getting, and which firmware did you use?
Re: New fan and thermistor aren't working
Posted: Mon Jan 08, 2018 9:43 pm
by norleck
Thermistor is reading 0. Not sure about the firmware version. Where do I check that?
Re: New fan and thermistor aren't working
Posted: Tue Jan 09, 2018 4:19 pm
by jk42
You can find your present firmware version in the connection log.
If you're unsure of which version is correct, please use the firmware selector tool at firmware.makergear.com
I would also suggest you open a ticket with us at
support@makergear.com
Re: New fan and thermistor aren't working
Posted: Tue Jan 09, 2018 10:24 pm
by ednisley
norleck wrote:with the Z motor mount broken off
Which put a mighty yank on the cables attached to the hot end and broke the thermistor wiring.
Turn off the power, unplug both ends of the thermistor cable, and verify:
- Connector at the thermistor is intact / undamaged
- Continuity of each wire between that connector and the other end at the RAMBo pin header
- RAMBo pin header is unbent / undamaged
If it looks good, then plug the thermistor into the cable, leave the RAMBo end unplugged, and verify about 100 k ohm resistance between the two pins at the RAMBo end. It should remain stable at 100 k ohm as you wiggle & jiggle the connector at the hot end and the cable braid.
I'd expect a broken wire either at the extruder connector or inside the braid at the first nylon tie securing the cable from the extruder to the frame.