Hey guys I am just letting you know my 3D printer is a geeetech prusa i3 pro B and I am running into a few problems. Today when I was using the 3D printer the hotend broke. The resistor came out of the hotend and almost caused a fire. This is the second time this as happened. I don’t want it to happen again. Maybe I was miss using the hotend I don’t know but I don’t want to buy a new hotend or extruder unless someone can confirm I was either miss using the hotend, I need a new extruder that is compatible with a different hotend, or maybe the hotend was faulty and I just need a new hotend and that will solve everything. By the way I am using an mk8 extruder with it’s hotend that can be attached to it. Thanks!!!
Kapton tape wrapped around the hot end will help keep the thermistor in place.
@PrintinAddiction Well first of all that only solves the resistor problem. Another problem I failed to mention since I didn’t think the thing could be fixed was that a wire came off the resistor and I am not sure how to fix it. Thank you though!!!
The wire should be crimped on. Also, there should be a grub screw that holds it in.
@Keith_Applegarth The wire is crimped on but it has snapped near the resistor in half. What should I do? Thanks!!!
new crimp? If it is broken too close to the resistor, then the resistor will need to be replaced.
You’ll need a new thermistor. If the wire snapped near the thermistor head, it means you didn’t properly strain-relief the rest of it. When that print head moves, the wires to the thermistor should not move at all except at a much higher position in the wiring, at a thicker segment of wire.
@Keith_Applegarth I don’t think that is an option. The thermistor needs replacing and I would rather buy a new hot end than do that. A hot end will be more guaranteed to work. Thanks!!!
@ThantiK how do I stop the wires from moving? Thanks!!!
Thermistors aren’t that expensive.
@Keith_Applegarth but the thermistor idea may not work and I don’t want to spend the money on a solution that may not work like a few other solutions I had to fix my printer. Thanks though!!!
To stop the wires from moving I used the hole in the middle of the heated bed, i zip tied the wires to that. This way is you tugged at the wires it would pull where they were zip tied and not at the solder joints.
If the wire broke and it continued heating you do not have protection in your firmware, a very dangerous setup. Update/configure Marlin correctly (if that is your firmware).
Thermistor should be easy to replace. Buy it off eBay or MakerFarm. E3d and MakerFarm have instructions on how to work on them.
@PrintinAddiction thanks I will try that.
@Oystein_Krog thanks and it did stop heating.
@Francis_Lee well the thermistor isn’t the issue as much as the resistor is an issue. Thanks though.
Hmmm I’m confused now haha… initially I thought you were talking about the power resistor (heating element). Then everyone was talking about the thermistor (sensor).
Whatever the issue is, parts will be cheap, and the solution is going to be fairly easy to resolve. I’ve fixed plenty of old J-Heads. You can do it! 
@Francis_Lee thanks!!!
@Noah_Schreiber - helps to use proper terminology - the thing that heats the nozzle is called a Heater Cartridge – Nobody has used resistors since 2007 or so. The thermistor is a resistor as well, so just saying “resistor” doesn’t actually distinguish what you’re talking about.