Changing the processor fo duet wifi v1.03!



  • I accidentally shorted my board when i connected a precision piezo to my duet WiFi and shorted the piezo disc to the ground. Wifi chip is surely fried & X1 clock not generating so expecting the processor to be gone as well. Can anyone guide me how to change this,(PS i have support for professional soldering) ??


  • administrators

    The WiFi module is easy to replace. Heat the Duet to 120C on a hotplate, use hot air to melt the solder, and very gently lift off the old module using tweezers to hold the end that overhangs the edge of the PCB.

    For the processor, use the hotplate and hot air tool again, but you will need a vacuum pickup tool to lift the processor off. Be very gentle because the fine PCB traces will lift off the PCB very easily when hot.

    After removing the old processor, use a no clean flux pen to clean the pads and hot air to solder the new one. For the WiFi module I prefer to remove the old solder from the pads using solder wick and solder the new module in place using a fine tipped soldering iron.

    There are lots of SMD rework videos on YouTube.

    HTH David



  • What about the firmware in the chip? Can you please point out where I can get those hex files I need to get them pre-programmed from the manufacturer itself! Also the processor in the attached picture is the one in duet v1.03 right?(just confirming)0_1552058673004_Screenshot_2019-03-08-20-31-34-280_com.android.chrome.png


  • administrators

    Yes that's the right processor. You can upload the firmware over USB using Bossa or SAM-BA, see the instructions on the wiki.



  • Is it possible that due to firmware erase clock may not work? I came to the conclusion that processor is dead, as the pc was not detecting the board, also the x1 clock was not working!


  • administrators

    I think the clock should work even if the firmware is erased, because without it the USB port wouldn't work. But I've never checked. If looking for the clock with an oscilloscope, look on XOUT not XIN, and use a x10 probe. Otherwise, connecting the scope probe may stop the clock.



  • Changed the processor and the WiFi chip! It still did not generate clock, so not detected in the pc! What to do?



  • Do you have clock signal now?
    Are all the supply voltages present?
    Is the reset line high?



  • Yes all supply is there 3v 3.3v, also the 12v works fine! But clock is not generating



  • @hedis how to check if the reset line is high?


  • administrators

    The reset line is pin 83 of the processor. It's also connected to one end of R106. the other end is connected to +3.3V. So both ends of R106 should be at +3.3V.

    Have you checked for solder bridges between the pins of the processor, and for pins not soldered down properly?

    I suggest you also check that both ends of L5 and L6 are at +3.3V.



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  • Connect the negative lead of your voltage meter to gnd somewhere on the board/power supply and only move the positive lead to the desired test point when you make these measurements.

    Just make sure that you have +3.3v on the reset line, then it should be in the correct state.

    Does the computer react when you connect the USB now after the CPU swap?



  • @hedis no computer does not detect the board!



  • @dc42 I have checked thoroughly no R106 on my board! When I checked PDF schematic it showed internal 100k in processor for reset. My board is duet WiFi V1.03



  • @dc42 my reset button is not moving properly once I press it doesn't move back! Can it be the reason? The voltage on the reset button is 3.03v



  • Voltage at l5=3.3v, l6=1.2v


  • administrators

    @yatinsd said in Changing the processor fo duet wifi v1.03!:

    Voltage at l5=3.3v, l6=1.2v

    What do you mean by I5 and I6 ?

    Which version Duet is it? I can't remember whether R106 has always been present or was added in a recent revision.



  • @dc42, mine is Duet wifi v1.03, I Mean the L5 & The L6 you asked me to measure if at 3.3v, in your last reply in this post.


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