26 Reply by josh.aeauto (edited by josh.aeauto 2015-08-10 15:16:34)

  • josh.aeauto
  • Member
  • Offline
  • From: South Carolina
  • Registered: 2014-12-29
  • Posts: 305

Re: 1.0A heater decoupled

Just one thing to bear in mind; resistance and continuity are related, but not the same. Continuity checks for low resistance (ie, a continuous path). Depending on your meter, your meter might see 2Ω as continuous, thus it beeps when you tested it. But if you have resistance of close to 0Ω, you would have a short, and that would mean a bad heater. But you won't know that until you actually check resistance.

I'm not sure how the davinci board works, but the board should supply 12V at the heater terminal UNLESS it has a failsafe to check resistance of the circuit, and ONLY when the heater is supposed to be on (12V = nozzle hot). I would doubt it has that sort of failsafe though. The light on the back beside the heater plug... does it only come on when you put the printer into nozzle cleaning mode or does it stay on constantly?

-Prusa i3 MK2s
-Airwolf HD2x w/ E3D v6 + Volcano
-Custom built Solidoodle 3 clone w/ E3D v6+ Volcano    -Solidoodle Press w/ E3D Lite6
Filastruder #1577

27 Reply by rushin

  • rushin
  • Member
  • Offline
  • Registered: 2015-08-04
  • Posts: 30

Re: 1.0A heater decoupled

The light stays on constantly. and I am pretty sure that's how it always been. I will check resistance of the heater tonight. What Ohm range am I look for?

Thank you!

28 Reply by josh.aeauto (edited by josh.aeauto 2015-08-10 17:06:42)

  • josh.aeauto
  • Member
  • Offline
  • From: South Carolina
  • Registered: 2014-12-29
  • Posts: 305

Re: 1.0A heater decoupled

rushin wrote:

The light stays on constantly

Then that's probably just an indication light that the board is receiving 12 volts from the source and has nothing to do with the heater circuit.

rushin wrote:

I will check resistance of the heater tonight. What Ohm range am I look for?

If it's a 25 watt heater, it will be 5-6Ω
for a 40 watt heater, it will be 3-4Ω

You want to look for a short circuit (around 0Ω) or an open circuit (no connection; infinite ohms; your meter will read OL or similar)

-Prusa i3 MK2s
-Airwolf HD2x w/ E3D v6 + Volcano
-Custom built Solidoodle 3 clone w/ E3D v6+ Volcano    -Solidoodle Press w/ E3D Lite6
Filastruder #1577

29 Reply by rushin

  • rushin
  • Member
  • Offline
  • Registered: 2015-08-04
  • Posts: 30

Re: 1.0A heater decoupled

Great thank you. I know its a 40W unit. Will measure today and post results.

30 Reply by rushin

  • rushin
  • Member
  • Offline
  • Registered: 2015-08-04
  • Posts: 30

Re: 1.0A heater decoupled

so looks like the heater is fine. reading is 3.8 ohms. Any other thoughts? what should be my next steps in figuring out this issue?

31 Reply by josh.aeauto

  • josh.aeauto
  • Member
  • Offline
  • From: South Carolina
  • Registered: 2014-12-29
  • Posts: 305

Re: 1.0A heater decoupled

rushin wrote:

so looks like the heater is fine. reading is 3.8 ohms. Any other thoughts? what should be my next steps in figuring out this issue?

Well, that's sortof unfortunate since it would be the cheapest thing to replace. Sounds like your board is bad. Maybe someone else has a board they are willing to sell or you can convert it to a RAMPS or some other board.

-Prusa i3 MK2s
-Airwolf HD2x w/ E3D v6 + Volcano
-Custom built Solidoodle 3 clone w/ E3D v6+ Volcano    -Solidoodle Press w/ E3D Lite6
Filastruder #1577

32 Reply by luc

  • luc
  • Member
  • Offline
  • Registered: 2014-12-17
  • Posts: 138

Re: 1.0A heater decoupled

You can disable the decouple test in FW, it may help you to see where/when printer behavior is wrong when heating

33 Reply by rushin

  • rushin
  • Member
  • Offline
  • Registered: 2015-08-04
  • Posts: 30

Re: 1.0A heater decoupled

luc wrote:

You can disable the decouple test in FW, it may help you to see where/when printer behavior is wrong when heating

How do I do that?

34 Reply by luc

  • luc
  • Member
  • Offline
  • Registered: 2014-12-17
  • Posts: 138

Re: 1.0A heater decoupled

line 44 of configure.h, change 1 to 0

//Decouple Test feature, do not disable it unless you know what you are doing!!!
//if you have decouple issue it means you have hardware issue or bad air flow management!!!
//this feature is a safety feature, if you disable it is dangerous!!!
#define FEATURE_DECOUPLE_TEST 0

35 Reply by rushin

  • rushin
  • Member
  • Offline
  • Registered: 2015-08-04
  • Posts: 30

Re: 1.0A heater decoupled

UPDATE! Heater decoupled error fixed! The issue was a damaged zero ohm resistor like somebody has mentioned. I was able to have a local small electronics repair place replace the resistor and now printer works again. It only cost like $25 with the new part.

I still have another issue with the printer. Now when I start printing something after a few layer I get a z-axis failure. I will try and see if I can post the error.