I’m always struggling to desolder high heat circuit boards like pc motherboards because they used high heat solder. Sometimes I can get it hot enough that I can mix in some lower temp solder but it’s always a pain. I’ve also used my rework hot air at 500* plus the soldering iron at 500* and gotten it, but that’s a pain as I only have two hands. Right now I’m replacing the Nec/Tonkin caps on a ps3. Fortunately removal is simple with a chisel, but getting the pads ready for soldering is a huge pita.

  • micronicle@discuss.tchncs.deEnglish
    2·
    2 days ago

    My experience with PC motherboards in regard to your question is to only use a soldering iron where a hot air gun is just not practical. The power surface mount FETs that are numerous and have large thermally efficient track/pads are the most difficult component to remove without damaging the PCB. Hot air and kaptan tape to protect close by components is essential. I have repaired hundreds of PC system boards. Where possible cut the component body off of the component legs before attempting to remove the through hole pins. Electrolytic capacitors will readily pull off of their legs by leaning them sideways for leverage then pulling to remove the can completely, meaning only the plated through hole need be heated with hot air, and rather than use a desolder tool or solder sucker as we call them which can easily damage tracking, using a very narrow nozzle on the hot air rework gun to melt the solder holding the pin in place while gently extracting the pin with snipe nose pliers and then keeping the solder in the plated through hole hot, blow air through the hole with a quick dab of the nozzle, perpendicular to the PCB will result in a good clean plated through hole with the least amount of damage possible.

  • cmnybo@discuss.tchncs.deEnglish
    8·
    11 days ago

    For multi layer PCBs like motherboards, you want a PCB preheater in addition to a good soldering iron. The ground and power planes will take a lot of heat. If they are already warm, they will need less heat from the soldering iron.

  • vext01@lemmy.sdf.orgEnglish
    6·
    11 days ago

    I bought an electric desoldering pump and it changed the task of desoldering forever. The tip both heats and sucks.

  • nilloc@discuss.tchncs.deEnglish
    3·
    11 days ago

    I’ve always used desoldering braid and patience. Always tinned first with 60/40 rosin core and some flux to get the heat flowing in faster and break the oxide layer.

    Maybe finding a stand to hole the reflow gun above your work to free up a hand would help.

    A good pcb clamp helps a lot too.

  • qupada@fedia.io
    2·
    10 days ago

    Performance wise, you’d struggle to beat a JBC station.

    I have an older version of this one, has been fantastic: https://www.jbctools.com/cdb-soldering-station-product-1605.html

    Price-wise, well that’s a whole different story. That station is about $600 USD and change, and individual tips start at about $40.

    What it does have though is damn near instant heating (it takes longer for the controller in mine to boot than it does to heat), hot-swappable tips (the metal comb-looking thing is to aid pulling the tip from the handle), and nearly 150 shapes of tips to choose from (see https://www.jbctools.com/c245-cartridge-range-long-life-tip-product-19-design-iron.html).

    Their other innovation (now somewhat commonplace) is building the element into the tip, letting them put significantly larger power output into comparatively low thermal mass tips. Does wonders for temperature control.

    Here’s a reasonable comparison of the older-style (Hakko, Weller) separate element/tip design against the JBC’s integrated: https://youtu.be/scvS2yeUH00