Correct position of D5/D6


As a follow up on my previous post, here how to replace the D5 and D6. The white multi-line on the component is the cathode. On the PCB footprint, rounded corners on one side indicate the cathode position. As they say, a picture is better than 1000 words:

(click for larger view)

And while removing the old parts, please make sure you follow the common sense approach:

  1. Wet the place with lots of liquid flux
  2. Replace solder on the pads with good quality 60/40 lead solder
  3. Heat up with enough heat (320 deg C) and alternate between two pads. Use absolute minimum force. Or use solder braid to heat up both pads the same time
  4. Clean the pad from flux before soldering the replacement part


4 thoughts on “Correct position of D5/D6

  1. Akio Mizuno

    MCHF COMPLETE KIT v 0.6 I bought has marking S4 mounted on D1, D5, D6.
    PMEG6010CEM is a marking CA.
    Please send me a marking CA diode.


    I am operating in my zero-sum practice of selling one hobby bit before spending money on a different hobby. I have been following the mcHF thread for quite a while and I am ready to begin. I have no experience with github or the like, so this is likely to be entertaining…
    Very little experience with SM parts and servicing. I see that D5 & D6 need to be replaced, and I had a question about procedures to remove them.
    Would it be acceptable practice to use a small dremel tool to slice the parts in half before un-soldering them?

    1. m0nka Post author

      Hello Paul,

      On the dremel tool – absolutely not! Basically there are two techniques for handling SMD parts:

      – automatic by a machine (this is what factories use)
      – prototyping technique (where all is done by hand)

      You need to use the prototyping technique. It involves simple soldering iron, liquid flux, and some SMD
      tools like scrapers, brushes and magnifying glass. Hot air station is a good idea, but not needed 100 %.

      To get a grasp of it please check my video on the STM32 soldering:



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