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Solved Temp shows 230C when stone cold at start up

Discussion in 'Troubleshooting' started by Rigmarol, May 26, 2016.

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  1. Rigmarol

    Rigmarol Well-Known Member

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    I installed CURA and it's showing the same 231C as the temp of the hotend and it's stone cold room temp unless I add to the 231C.
    Rats. Looks like a Thermister to me.
    (with my 4 whole days of experience LOL)

    Edit to add: I've put in a help ticket we'll see what I'm advised.
     
    #21 Rigmarol, May 26, 2016
  2. Geof

    Geof Volunteer Moderator
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    Do you have a multi meter? You can ohm it and post your results (ohm the thermistor at the connector)
     
    #22 Geof, May 26, 2016
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  3. Rigmarol

    Rigmarol Well-Known Member

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    I might try that but in the morning when my eyes are fresh. I don't do well close up and by evening I have a bit more trouble. New glasses should be here in a week or so, I'm hoping they help.

    I might ask my friend to use the meter for me.
     
    #23 Rigmarol, May 26, 2016
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  4. Geof

    Geof Volunteer Moderator
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    Im guessing the thermistor is damaged from the high reading when cold. The ohm test gives you something to try though so we can keep troubleshooting if it ohms ok while your waiting on parts
     
    #24 Geof, May 27, 2016
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  5. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    That or a bad connection making it read higher than it should . Those are NTC thermistors so a higher temp is a lower resistance. All you can do it make sure nothing in the wiring to the thermistor is grounding out or causing a near short. Read the resistance across the thermistor from the ramps connection (with power off).
     
    #25 mark tomlinson, May 27, 2016
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  6. Rigmarol

    Rigmarol Well-Known Member

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    Good morning, I was able to measure the thermister with my meter.
    I am getting a reading of 118.0K.

    Now, I have no idea what it is SUPPOSED to read so at least I know it's not shorting or open.
     
    #26 Rigmarol, May 28, 2016
  7. Geof

    Geof Volunteer Moderator
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    I believe they are 100kthermistors so that's not to terrible.

    And the wiring is secure in both the connector near the hotend and the ramps ?
     
    #27 Geof, May 28, 2016
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  8. Rigmarol

    Rigmarol Well-Known Member

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    I'm sure all wires are secure and in good condition because I was extremely careful putting it in. However, at this point I probably should take it out and put it back in to be sure.

    When you refer to "ramps" I'm not sure what you are referring to. The thermister plugs into a connector higher up on the assembly and it presses in to the hot end near the the tip (square block).

    Thanks.
     
    #28 Rigmarol, May 28, 2016
  9. Geof

    Geof Volunteer Moderator
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    The ramps board is underneath your printer. You have to remove the bottom cover(the fan wires are very short so be careful) and on that board is a t0. That is your thermistor connection on your ramps boards (part of the control board)

    Seeing as how you haven't been in there it probably isn't a problem but would be good to verify it didn't fall off or come loose. Taking the thermistor back out and reinstalling would be first
     
    #29 Geof, May 28, 2016
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  10. 3D Printer Man

    3D Printer Man Guest

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    Get the wiring of your board and make sure every wire is secure.
     
    #30 3D Printer Man, May 28, 2016
  11. Rigmarol

    Rigmarol Well-Known Member

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    Ok, I'll pop off the bottom and take a look see now that I've taken the thermister out, tested it again to be sure it still registered. and I've carefully put it back in and tested again. Whew! micro surgery for my old eyes LOL.
     
    #31 Rigmarol, May 28, 2016
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  12. Rigmarol

    Rigmarol Well-Known Member

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    A great suggestion. Any suggestions on where a pdf file might be downloaded from, I couldn't find one.
     
    #32 Rigmarol, May 28, 2016
  13. Geof

    Geof Volunteer Moderator
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    There arnt really any documents regarding our printers other than what members have posted. Let me try to dig up a picture and ill circle the connection
     
    #33 Geof, May 28, 2016
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  14. Rigmarol

    Rigmarol Well-Known Member

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    Wonderful, thanks!
    I have the bottom off now and have checked all the connectors and all are seated fine. All looks normal and nothing seems loose.
    I'll wait to put it back together until after your photo.
     
    #34 Rigmarol, May 28, 2016
  15. Geof

    Geof Volunteer Moderator
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    Ok so it wont let me uoad from my phone. There are two white connectors. On the board they are labeled t1 and t0. These are thermistor connections to the board. Unplug them and plug then back in.

    If that doesnt work switch the t1 and t0 connectors on the board and let us know what the bed reads
     
    #35 Geof, May 28, 2016
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  16. Rigmarol

    Rigmarol Well-Known Member

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    I upload my phone pictures to PhotoBucket. I host pictures there and most all Forums will accept the links.

    I took a picture of my board along with a picture of the Robo on it's side for orientation:
    I don't see anything labled with a "T" anything. But I'm really bad at close up right now. New glasses due in a week or so.
    [​IMG]

    [​IMG]
     
    #36 Rigmarol, May 28, 2016
  17. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    Bottom right hand section in this picture @Geof posted in his RAMPS replacement thread. You can just make out T0, T1, T2

    [​IMG]
     
    #37 mark tomlinson, May 28, 2016
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  18. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    On yours they are in the same spot (mostly) right next to that white connector.
     
    #38 mark tomlinson, May 28, 2016
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  19. Geof

    Geof Volunteer Moderator
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    Those 2 in the yellow. :) thank you for uploading the picture. I need to figure this phone out lol
     

    Attached Files:

    #39 Geof, May 28, 2016
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  20. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
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    The sad part of this exercise is that when the temperature is not reading correctly you only have a few things it can be. And even less 'reasonable' ones :)

    Thermistor bad, wiring bad (or not plugged in correctly), RAMPS bad. The Arduino? Nah... I don't buy that one, but I suppose it is extremely remotely possible:)
     
    #40 mark tomlinson, May 28, 2016
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