Solved Extruder Not Heating

Hello,

Hope I can get some guidance - Issue current assumption RAMPS but heres the details

Issue - Extruder does not heat up no heat at all, clicking pre-heat will show up arrow in temp setting but temp appears to go down. This was the same issue with the stock thermistor.

Cause - My Robo 3d has the same plug ends for both the extruder and the thermistor, came that way from robo. While working to repair a leak in my extruder, I hastily plugged the extruder into the thermistor plug and vice versa and attempted to heat.

Fix attempts - Not sure of actual cause I used this as an excuse to order a new thermistor (stud from Print Solid), and the E3D v6.

New thermistor result - temperature shows extruder idle temp at (25-30 degrees)
Test old heat end - Hooked to a weak 12 volt battery the heat end does start to heat up.
Visual inspection of boards does not show loose wires or burn spots. Visual inspection was done with boards still connected to each other but unscrewed from the mounts.

( Digital voltmeter set at 20 DCV) Check volts at - Extruder plug 0.00 same when preheat
Thermistor plug - 5 volts steady prea heat or not.

Personal skill sets - I can take things apart a reassemble fine, schematics I can read with guidance, can solder wires i don't try to solder boards, have both digital and analog volt meters can use and read them ok.

If this does sound like RAMPS and through instructions I confirm it I would appreciate reference to a board supplier.

Thanks for the assistance!

 

Hi Mark thanks for the info, ill get a look at D10 here shortly. If indeed the Mosfet on the RAMPS is shot what is a resource to buy e replacement. If i just google RAMPS board will i find what i need?

Any coding progrAming needed when replacing or is the RAMPS just controled by the audrino board and is plug in play so to speak?

 

I tried D10 with the heater command to preheat no voltage, as a double check I also looked at D8 with the bed command to preheat also not voltage,.

Thanks for the board direction, went ahead and ordered, Prime has its uses sometimes. Ill do the board swap as soon as they come in.

A question on fail safes - I assume the printer can be on its side with the extruder and thermistor hanging free (did this to access the board and test D8 and D10. This wouldnt keep the machine from warming would it?

 

Crazy but glad to know that as I was wondering if my readings were wrong.
I'm going to mark this one "Partially Solved" when I get the boards in (ETA Tuesday) I get them installed and update the thread.

Thanks for all the info and assistance Mark.

 

Original ramps had a burn on the bottom right side close to the D10.

Where I'm at - Almost there - Board is in place and that went pretty smooth except for getting things in place and realizing I didnt install the jumpers . The hitch I find myself missing the 11amp right in front of the power supply plug
This would leave me without a case fan and I don't want to do that.

Cant really tell on the schematic but is there another open set of pins that has constant power to run the 12 volt case fan.

 

Awesome thank you Mark, with you help I was able to find the I2C and good to go. Time to button this up and verify function. Will report and hopefully be marking solved shortly.

 

Just for reference on old board the burn mark is on the connection from mosfet to D10.

Current - No dice - Same issue, hit preheat and temp goes down.

Next steps -
I'm going to pop back open the case and check connections. if all good Ill open up the wiring strand and follow wires looking for burns and or breaks.I will also take a moment to recheck voltages in the plugs when preheat is activated.

Any other suggestions? beyond the above

 

These schematics really help, thanks for providing. It is Q1 that is dead on the old board. On the new board I have yet to check between but I will after getting through the wire bundle. Just a note both fans at the print head are working.

Ill report back once I get through all the wiring. Thanks again Mark for all the assistance.

 

Thanks Mark,

After doing some wire checks all feel fine and no visible burn marks from the boards to their connection point. Thinking the heat element may be bad i wired up my E3D v6 heating element and fire up matter control. Attempted to preheat and received the same temp drop. The heating element (assuming this is me using a different word as the core you mentioned) is not heating I kept my hand near it and touched it to be sure.

At this point I hit the preheat for the bed to check results and it also is showing temp drop / cooling down now.

My next steps is to pull the boards again and do visual inspections, beyond this I am at a complete loss.

Any guidance is appreciated.