Trouble with the extruder not heating.

Alright first things first, I've had this great printer for quite a while now and have had zero problems up until a couple of months ago. I have had some incredible prints up until randomly my extruder will just not heat. Sometimes, if I'm lucky I'll wiggle the pin connector a little and the heat will kick on but only for a few minutes. I've read a few threads on here that they used cheap parts in that area, but what exactly is the fix?

I have sent 2 emails over the course of 2 months and haven't gotten a response from anyone, so I figured I'd pick your brains. I'll be taking a volt meter to it tonight to try and figure out what the problem is.

I would really appreciate the help so I could get back to printing and not having a big expensive paperweight.

 

Do you get an error message in terminal about min/max temp error? Sounds like your thermistor has a loose circuit

 

Nope, no errors whatsoever. It's like the heat is activated by showing the little up arrow by the temperature, but the number just doesn't move at all.

 

Are you getting 12v off of D10 when you activate the heater?

 

I'm not sure, I'll check this evening and get back to you. Thanks for helping out.

 

Alright I thought I'd be alright doing this, but when it comes down to it I'm just cautious and afraid of breaking something even more. Would you mind giving me a little description as to what to test on it and where?

 

On the ramps board to the left, there's 3 output ports. D10, 9, and 8. D10 runs the extruder port.

Carefully measure on the two screw terminals by D8 so as to not short across the probes. Do this while it's supposed to be heating the extruder. If it's supplying 12v then the heater cartridge might have gone bad. Measure the resistance across these two points as well.

 

Ok so D10 is perfect. We're getting 12v from it, along with 12v from extruder pins. It may very well be the heater cartridge, how would I go about replacing this?

 

What's the resistance across D10? The heater cartridge is just a standard 12v 40w cartridge heater. Something like this: http://www.amazon.com/Reprap-Cerami...1730&sr=8-1&keywords=40w+12v+cartridge+heater

If you printer is new you can contact team robo and they should be able to send you a replacement.

I'm making the assumption you have either a black ceramic J-head or a hexagon.

 

Can't get a good reading, it acts like it's open.

Thanks a ton Mike, gonna order a couple of those for backups and see if we can get it back up and running. It looks like a ceramic one.

 

If it's a ceramic axial heater you want between 5.6ohm and a 6.8ohm. Not sure if the heater cartridge fits in the axial slot.

http://reprap.org/wiki/J_Head_Nozzle#Off-The-Shelf_Parts

Just to be sure check the wiring around the heater. Might just be a loose cable.