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

Unanswered MEGA 2560 R3 replacement

Discussion in 'Troubleshooting' started by PTIschool, Mar 5, 2021.

  1. PTIschool

    PTIschool New Member

    Joined:
    Jan 21, 2021
    Messages:
    22
    Likes Received:
    0
    Looking for a replacement mega R3 board because I think I fried mine when trying to resolder the data cable connector because it became loose. Seems like I have had this problem with the nanos also. Don’t understand why a small solder would knock the board out. Any help would be appreciated. Thanks.
     
  2. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,657
    Likes Received:
    7,316
    PTIschool likes this.
  3. PTIschool

    PTIschool New Member

    Joined:
    Jan 21, 2021
    Messages:
    22
    Likes Received:
    0
    So I bought the mega replacement and put it in my machine, but my lcd is still showing the hotend at 192 even though its not even plugged in. Any ideas?
     
  4. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,657
    Likes Received:
    7,316
    Bad thermistor or bad wiring/connection in the line to the thermistor.
    If the thermistor is reading too high or too low remember this:
    The ones Robo uses are NTC thermsitors (negative temperature coefficient.
    This means that as the resistance goes down the actual temperature is going up (and vice-versa).
    With it reading high at room temperature that means the thermistor is shorted or there is an short circuit in the wiring (lower resistance => higher indicated temperature).
     
    PTIschool likes this.
  5. mark tomlinson

    mark tomlinson ༼ つ ◕_ ◕ ༽つ
    Staff Member

    Joined:
    Feb 21, 2013
    Messages:
    23,657
    Likes Received:
    7,316
    Honestly with most Printer sensors -- if you think the electronics is the problem it is most likely the RAMPS board and not the Arduino.
    I have seen some Arduino failures, but that is not the most common component (the RAMPS is the most common failure).
     
    PTIschool likes this.
  6. BrooklynBay

    BrooklynBay Active Member

    Joined:
    Apr 7, 2018
    Messages:
    425
    Likes Received:
    49
    Swap the hotend & bed temperature sensor wiring on the RAMPS to see if the reading changes or remains the same. This will help you troubleshoot the issue if you don't have a spare temperature sensor to test with.
     
    PTIschool and mark tomlinson like this.

Share This Page