1. Got a question or need help troubleshooting? Post to the troubleshooting forum or Search the forums!

Solved Robo R1+ MAXTEMP

Discussion in 'Troubleshooting' started by Victoria Nedbal, Sep 21, 2018.

Thread Status:
Not open for further replies.
  1. Victoria Nedbal

    Joined:
    Sep 21, 2018
    Messages:
    33
    Likes Received:
    4
    Hi all,

    Two of the Robo R1+ that I work with have given us an error through OctoPrint saying "Temperature heated bed switched off. MAXTEMP triggered!!"

    This has made it impossible for us to connect to the printers remotely and when a computer is connected it still has the same error and will not let anything to print.

    How can we fix this?

    Thanks in advance for the help
     
  2. Geof

    Geof Volunteer Moderator
    Staff Member

    Joined:
    Nov 9, 2015
    Messages:
    6,757
    Likes Received:
    2,339
    hi there,
    Max temp is a thermistor short. Could be the thermistor itself is shorted, a short in the wiring, or a main board shorted togather.
     
    WheresWaldo and mark tomlinson like this.
  3. Victoria Nedbal

    Joined:
    Sep 21, 2018
    Messages:
    33
    Likes Received:
    4
    Thanks for getting back so quickly. I've been trying to go more in depth about this issue by emailing Robo but I haven't gotten much of a response/they said they've never had this error before and it's happened to two of our printers. I connected it to MatterControl and it's still coming up with this error.
    upload_2018-10-9_10-32-26.png
    Do I need to replace the thermistor? Or the main board? If so, how would I go about doing this?

    Thanks for all your help, sorry for the late response.
     
  4. Geof

    Geof Volunteer Moderator
    Staff Member

    Joined:
    Nov 9, 2015
    Messages:
    6,757
    Likes Received:
    2,339
    Do you have a multimeter and are you decent with taking things apart and putting them back togather? What I would do is remove the bottom cover, unplug the thermistor for the bed and put a multimeter on continuity check between the two pins. If it shows a short (beeps) then the thermistor is no good and the bed should be swapped.
     
    mark tomlinson likes this.
  5. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,912
    Likes Received:
    7,338
  6. Victoria Nedbal

    Joined:
    Sep 21, 2018
    Messages:
    33
    Likes Received:
    4
    I can try that. The bed thermistor is located under the foam right? Also, I don't know if this is related, but I just tried to home the printer and it kept making this sound. Does it mean anything?

     
  7. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,912
    Likes Received:
    7,338
    Yes, but I think he means disconnect it from the RAMPS board under the printer (remove bottom cover) and then read the resistance back. Here is the board (look for heat bed thermistor):

    Annotated Ramps.jpg

    With the printer upside down and the cover removed, this is the top-most electronics board
     
  8. Geof

    Geof Volunteer Moderator
    Staff Member

    Joined:
    Nov 9, 2015
    Messages:
    6,757
    Likes Received:
    2,339
    Yes exactly what I mean! Thank you :D
     
  9. Victoria Nedbal

    Joined:
    Sep 21, 2018
    Messages:
    33
    Likes Received:
    4
    So I put the mutlimeter on the heated bed thermistor pins and it gave the following result. upload_2018-10-9_11-34-16.jpeg
     
  10. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,912
    Likes Received:
    7,338
    Ummm? With power off?


    Negative resistance is ... unusual to say the least :)


    and (to be clear) we want to read the resistance of the wire back to the thermsitor, not the pins on the board so you need to disconnect it from the board and then read the resistance of the wire back to the thermsitor.
     
    Geof likes this.
  11. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,912
    Likes Received:
    7,338
    You will also probably need to put it on the 200 KOhm scale since the thermistor should be about 100k.
     
    Geof likes this.
  12. Victoria Nedbal

    Joined:
    Sep 21, 2018
    Messages:
    33
    Likes Received:
    4
    Ok, sorry about that. This is how i set up the multimeter this time. upload_2018-10-9_12-20-13.jpeg
    and I got a result of 111.4kOhms
     
    mark tomlinson likes this.
  13. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,912
    Likes Received:
    7,338
    OK, that is good. Close to 100 kohm which is what the thermistor is rated at.
    So now plug it back in, reassemble it and flip it back over and see if you can heat the bed.
    What is it reading at the start?
    Does it track it as it heats up?

    If you get the same error then we need to suspect either a faulty thermistor or a bad RAMPS.
     
  14. Victoria Nedbal

    Joined:
    Sep 21, 2018
    Messages:
    33
    Likes Received:
    4
    Right when I connected the printer this is what it says its reading and both the extruder and bed are cold/room temperature.
    upload_2018-10-9_12-40-58.png
     
  15. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,912
    Likes Received:
    7,338
    OK, that is bogus and means that there is a bad connection or a bad thermistor there.
    Since you already checked the connections I would suspect the thermistor itself is damaged.

    If you are under warranty do give Robo a call and get that bed replaced.
    Out of warranty you can use a standard thermistor and do some disassembly/reassembly to replace the bed thermstor.

    We can probably find a thread with details on this or tell you enough to get it done :)
     
  16. Geof

    Geof Volunteer Moderator
    Staff Member

    Joined:
    Nov 9, 2015
    Messages:
    6,757
    Likes Received:
    2,339
    swap thermistors on the board. Take the hotend thermistor and plug it into the bed location, take the bed thermistor and plug into the hotend location. Please turn on and see if it still shows a max temp but on the hotend.

    In that case I would rekon the board is faulty.
     
  17. Victoria Nedbal

    Joined:
    Sep 21, 2018
    Messages:
    33
    Likes Received:
    4
    So, I work in a 3D print lab at my University and we have 2 working and 2 non-working robos. I swapped the bed from a working Robo and the bed comes up with the same temperature shown. Any idea what the problem could be if it's not the physical bed?
     
  18. Victoria Nedbal

    Joined:
    Sep 21, 2018
    Messages:
    33
    Likes Received:
    4
    I will try swapping the thermistors, sorry I posted that without refreshing first
     
  19. Victoria Nedbal

    Joined:
    Sep 21, 2018
    Messages:
    33
    Likes Received:
    4
    By swapping the thermistors I get basically the same results.
    upload_2018-10-9_14-17-52.png
     
  20. Geof

    Geof Volunteer Moderator
    Staff Member

    Joined:
    Nov 9, 2015
    Messages:
    6,757
    Likes Received:
    2,339
    Sounds like either a ramps/arduino issue to me honestly. Expecially since you can swap beds with no change (I assume this is a working bed off another printer). To verify (and your ok with it) swap boards between units and the problem should follow the board.
     
    mark tomlinson likes this.
Thread Status:
Not open for further replies.

Share This Page