Hotend issues

This is what i have sent off to support any ideas what may have caused this issue? Have you experience anything similar to this?

Hello,
Well I seem to have another problem and thought it would be okay to simply reply to this email instead of sending a new one. The hot end on the taz 4 will not go above 36c and “failed” sometime during my print. I was printing ABS for roughly five hours came back to find that the hot end had decreased from 235 down to 37-36 by itself. The hot end was cool to the touch and the filament as far as i can tell had no wear(the main turning gear was not moving during this process). I attempted to changed the temp via the control option, but was still listed under 235 and changing the temp to 230 made little difference. The hot bed itself maintained a steady temperature of 85 till i restarted the machine. Even after the machine restarted the hot end would not go past 36, but instead would idle at this temp. I’m currently using the “old” hot end as my complementary all metal hot end is still in the mail. Any help getting the hot end working again would be greatly appreciated! Thanks for the help, Jordan.

This could be anything from a broken wire going to the resistor in the hotend or a resistor gone bad. Could also be a blown mosfet or fuse.

If you have a multimeter you can check the continuity of the resistor to see if its open. It should read around 5 ohms but anything close means it’s not open. Also examine the small wires and crimp connectors going to the resistor and thermister to see if they appear unbroken (the tiny crimp joints have failed on me before).

Next I would say smell the controller box (where the holes are for the fan) if the mosfet blew it will likely stink.

Don’t have a multimeter, but can say that there is no smell emitting from the taz. I attempted to heat the hot end again but it will not leave a temp of 27 now. Could the element of went bad?
Here some pictures if it helps at all.



It looks like you’re already working with Brent- but like he suggests, the usual culprit of a hot end not heating will be the heater resistor. I’m glad to see that you two are getting things sorted!

Here’s a handy heater resistor replacement guide for when you two confirm it’s the resistor: https://ohai-kit.alephobjects.com/workflow/Budaschnozzle_resistor_thermistor/