Unanswered Extruder won't heat up.

That must be the older model mark talked about that needed a rubber boot to hold it in place. I'd suggest the e3dv6 upgrade get that hotend sorted I'd suppose some very high temp silicone could seal it in there??? @mark tomlinson probably knows much better than I do

 

No not a software / firmware issue. Hardware issue. That is still probably a bad thermistor or a bad wire to it.
Kapton tape can be used to wrap around the heater block and secure it if you need, but at this point you probably need a new thermistor.

Just make sure you have traced this all the way back to the RAMPS board and that there are no shorted/open circuits in the wires from there to the thermistor.

 

Id agree with mark, hardware. I'd guess since the thermistor ohms what appears ok that it's in the wiring, I think I'd fix up that wiring correctly and see where your at. With the thermistor being held in with tape or a boot I'd hit up printedsolid.com for the E3Dv6 and lcd bundle

 

That's odd. Known good thermistor and ramps= bad heater? @mark tomlinson ?

 

Sounds more like a faulty RAMPS. If you swap the bed thermistor to the place on the ramps that the extruder thermistor normally lands what does the software think the extruder is reading? Is is STILL 200 or room temp?

 

Yes, that makes sense and it is pretty obvious that it is a bad thermistor.
You verified the board works and if you have checked the wiring from the board to the thermistor is good then that just leaves the thermistor.

Under warranty contact Robo directly from the contact page on their main website. If you are out of warranty I'd suggest replacing it with a metal stud thermistor. They are far less fragile:

https://printedsolid.com/collections/accessories-and-upgrades/products/screw-on-m3-stud-thermistor

you can get them where ever you like

 

OK, you need to be more clear. You posts are a bit of a mess.
If the bed thermistor reads correct hooked up to the bed thermistor connection on the RAMPS and incorrect hooked up to the hotend thermistor connection on the ramps then the RAMPS board is faulty. This also means that if you take the hotend thermistor and connect it to the BED thermistor connection on the RAMPS that it reads room temperature.

If those two statements are TRUE then you have a bad ramps.
Contact Robo for the replacement part if you are under warranty.

 

OK, that sounds like a bad RAMPS. The firmware is probably the reason it will not heat if it sees the extruder starting off that high (when you hook it up to the bed thermistor connection it thinks that is the bed so that wouldn't help).

Contact Robo as I said for at least a RAMPS. They may also want to just swap the extruder as well, but at a minimum the HOTEND thermistor channel on that RAMPS is defective. RAMPS issues are rare, but not unheard of.

 

Exactly what printer version do you have? An R1, an R1+ or an old beta? What upgrades have you added (those matter too).

That is what matters for the firmware (not that this a firmware problem -- I see no evidence of that).

 

If it is an R1 then it is not the Beta

That firmware looks fine for an R1. There are no major fixes or differences in any of the firmware versions, all minor tweaks or adjustments due to differences in the printer models.

 

Well, you only have so many things that can be the problem you just need to sort out which one it is:
1) the thermistor itself is bad
2) the wiring from the RAMPS to the thermistor is bad
3) the arduino has totally bogus value for the extruder thermistor type in the firmware
4) the RAMPS is bad

(OK, in really rare cases I guess the arduino could be bad, but that is more likely to result in nothing working not just one bad sensor. )

Also I suppose the software (matter control) could be screwed up (more than it normally is) so try something else (like repetier host) and see if the symptoms are the same.