2-mm pitch female headers from--where else but--China. The gold-colored pins have been unwittingly engineered such that they wick up solder so efficiently that solder goes all the way up the header and effectively clogs the portion into which male header pins plug into.
I had to desolder the female headers on that red USB adapter board because of this problem. And just my luck the female headers I bought are the very same type installed by the manufacturer on their board! So soldering the new headers was anxiety-provokingly fiddly.
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| The gaps within each pin of the female header allow solder to wick into the inner recesses and clog the socket, thus rendering the header unusable--boards with male headers cannot be plugged in |
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| A new 2-mm female header just soldered in place |
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| In contrast is this 2.54-mm (0.1") female header |
