I have a controller for an electric throw blanket that I would like to repair, but I have no experience soldering on boards

You can see at bottom left a yellow box and a resistor. Something has burnt out in this area, and likely both will need to be replaced at a minimum

I would also need help identifying parts. The yellow box is embossed ‘Tenta’ and has printed on the side ‘TC MEX/TENTAMKP 0.1 uf 275VAC’ with some other markings obscured or damaged

Is this an achievable project?

  • OfCourseNot@fedia.io
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    2 days ago

    To the second and third issues, I think they happened because of bad settings in the wave soldering machine, and/or not prepping the board beforehand. Maybe the wave was to high, or the speed too slow. Many times you have to cover the smd components with a bit of painters tape. Even the orientation of the board on the frame can matter.

    • DosDude@retrolemmy.com
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      2 days ago

      There’s specific wave solder glue for smd components. Most likely all components were glued down. You can still see the off-white glue on the ICs in between the leads.

      The parts that should not be soldered are usually masked off. Either with a mold or kapton tape/flexmask. Never Painters/scotch tape, since it will melt and/or burn.

      • OfCourseNot@fedia.io
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        2 days ago

        Don’t know about the glue thing, the smds were put by a machine, but they would move like the one in the picture if you didn’t set the machine right. I can’t say for sure with that resolution but I think those white things are the shiny reflections on the pins/solder. I will look into these smd glues tho, that could come handy.

        And about the tape I have to say that my experience with wave soldering is not very vast, literally just one place, but they used painters tape, of the cheapest kind, and it worked just fine—no melting (it’s paper?), and no burning since the solder doesn’t get that hot (~200°C), the tape might stay a bit wet from the flux also idk.

        • DosDude@retrolemmy.com
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          2 days ago

          It looks like a board where they indeed probably put the components on by machine, however without solder paste, since it was going through the wave solder anyway. But you would need to glue the components down then.

          That’s why there is so much excessive solder. If it was printed with solder paste, it wouldn’t have this much solder.