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I'm soldering my first shortwave radio kit. I've got to soldering the headers which will take the 2.5" touchscreen display. I know this may be obvious, but best to check, is the middle and right terminal in the photo not solderable? They don't seam to have the copper for solder to attach to. I assume that the kit just doesn't require these connections to the display?

Non solderable terminals on mcHF shortwave radio kit

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  • \$\begingroup\$ That's kind of odd. Is the via throughplated? What does it look like from the top? Are there traces running from those holes at all on either side? \$\endgroup\$
    – DKNguyen
    Commented Dec 13, 2021 at 22:55
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    \$\begingroup\$ It looks like they put solder mask over the pads. \$\endgroup\$
    – vir
    Commented Dec 13, 2021 at 22:56
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    \$\begingroup\$ @crasic A burnishing/fiberglass pen works best. Looks like a eraser pen but with fiberglass bristles. Also works to remove corrosion off contacts. \$\endgroup\$
    – DKNguyen
    Commented Dec 13, 2021 at 23:01
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    \$\begingroup\$ are you certain that you placed the component on the correct side of the board? \$\endgroup\$
    – jsotola
    Commented Dec 13, 2021 at 23:07
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    \$\begingroup\$ I do not see soldermask-covered copper pads. I see fiberglass (FR4, the brownish color), then soldermask over FR4 (the dark green ring), then soldermask over copper pour (light green). I would think this means these pins do not need to be soldered, but more information on the kit would be useful \$\endgroup\$
    – DerStrom8
    Commented Dec 14, 2021 at 2:04

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From what I can see from the picture there is no copper in the via, just soldermask. So as indicated in the comments, either the PCB stackup is incorrect or you placed the component on the wrong side of the board.

Regardless, these should definitely be plated through like an ordinary via, so the PCB is incorrectly designed/manufactured. And they should not be round vias but ideally oblong similar to the shape of the leg. There should be as much metal to metal connection as possible, professional soldering does not involve large air gaps.

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