Powerloss/reset when current exceeds 6A



  • Good evening,

    Last week my printer started to get random power loses when printing.
    Today it stopped working. When I unplugged everything to Check the individuell component and connections it showed that the duet wifi board seems to reset when it trys to draw more then 5A. The resett looks like a really short powerloss.
    For example:
    switching the headbed(12V, 15A) to 60° C via the webinterface - the Status LEDs flicker and the webinterface loses connection for short time like when the plug is pulled and put back in.

    the steppers or hotendheater (12V, 5A) work alone. using them together ends in the same result as with the headbed.
    I habe double checken the psu and tried different psus, which work with my other printers.

    I have been using this duet wifi board without a changing setup for around 6 month with aprox 600h printing time.

    Thanks
    TRU



  • This is a low probability but it's important to remember the cause of problems aren't always the obvious ones. My BigBox shut down multiple times for no obvious reason and finally turned of and stayed off.

    I assumed it was the power supply. I ruled out a blown fuse and replaced the power supply, but it was still dead.

    0_1533402589178_15f6b3a9-5f43-4ec4-966e-ca6d6928ca50-image.png
    As you can see the power switch failed, melted the plastic casing, and burned the tinning off the copper wire that goes to the switch terminal blade.



  • The board gets power. I can measure the voltage at the hotend heater connection. The problem occurs when more components are switched on.



  • Do you see any visible damage to the board or connectors? Melting scorch marks? Loose fittings?


  • administrators

    Check that the screws in the VIN terminal block are still tight.



  • i had to replace the Main terminal block, therefore the solderingspots are not pristine anymore.
    I did some test cycles the last hours.(each of the 4 scenarios were tested 20 times) it is always the same:

    1. Running all three steppers (homing, calibration, random moves) - no problem

    2. Heating the hotend alone - no problem

    3. Hotend with steppers - instant powerloss (short flicker of LEDs and webinterface disconnect)

    4. Activation of heatbed - always as with Hotend and steppers

    (while doing this I monitored the voltage between VIN & GND - there was no voltage drop whatsoever)

    So I can rule out a loose connection.


  • administrators

    @tru said in Powerloss/reset when current exceeds 6A:

    i had to replace the Main terminal block, therefore the solderingspots are not pristine anymore.
    I did some test cycles the last hours.(each of the 4 scenarios were tested 20 times) it is always the same:

    1. Running all three steppers (homing, calibration, random moves) - no problem

    2. Heating the hotend alone - no problem

    3. Hotend with steppers - instant powerloss (short flicker of LEDs and webinterface disconnect)

    4. Activation of heatbed - always as with Hotend and steppers

    (while doing this I monitored the voltage between VIN & GND - there was no voltage drop whatsoever)

    So I can rule out a loose connection.

    It sounds extremely like a bad connection to me. Where did you measure the voltage between VIN and ground?

    Have you tried monitoring the VIN voltage reported by the Duet, when you run the stepper motors and when you heat the hot end?



  • Good evening,

    the duet wifi stopped working completely, so I removed the terminal block and found smoldered or burned spots beneath it and on the block itself. I have ordered a new one. Additionally I would like to check the fuses, but i cant find them or their values in the wiki.

    Regards
    TRU


  • administrators

    @tru said in Powerloss/reset when current exceeds 6A:

    Additionally I would like to check the fuses, but i cant find them or their values in the wiki.

    https://duet3d.dozuki.com/Wiki/Connector_and_spare_part_numbers



  • Good evening,

    I changed the terminal block and the problem is still there.
    As soon as at least one heating device gets activated the board behaves as if the reset button has been pushed.

    I can still print (without heatbed), when I power the hotend directly with a PSU and a mosfet (IRF520) with the signal from the E0 terminal block.

    Is it possible to send in the board for a cost estimate/repair?

    Regards
    TRU


  • administrators

    How old is your Duet, and which country are you in?



  • Good evening,

    It is a duet wifi (should be v1.03), which I bought 11 month ago at makerdise.
    I am from germany.

    Regards
    TRU


  • administrators

    I have emailed you.


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