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I am very inexperienced at electronics, but I have recently tried to connect a wireless chip to my microcontroller. I soldered some header pins to my board to allow me to remove the chip when needed or to change it.

Trying to test it by sending a message and printing it to a terminal on my PC.

However when I press send the chip doesn't appear to be working, but if I remove the chip and wiggle it about as I am inserting it the message sends. This indicates to me that there is a poor connection somewhere. But I have no idea how I would trace this.

Any suggestions?

enter image description here

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  • \$\begingroup\$ A photo of that female would really help. \$\endgroup\$ – Alexxx Feb 4 '16 at 16:15
  • \$\begingroup\$ Or a simple description what kind of header it is. \$\endgroup\$ – Alexxx Feb 4 '16 at 16:17
  • \$\begingroup\$ Below are some links to the header I am using, it is the 4x2 headers I am having problems with. I have also included a photo of the soldered connections, which are to the right of the QR code. \$\endgroup\$ – user3473406 Feb 4 '16 at 17:05
  • \$\begingroup\$ imgur.com/gr9K1ps imgur.com/lqTOGaq imgur.com/BEi0PVX \$\endgroup\$ – user3473406 Feb 4 '16 at 17:05
  • \$\begingroup\$ I don't see any headers in that photo. \$\endgroup\$ – Olin Lathrop Feb 4 '16 at 20:40
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The connections to the 8-pin SPI header don't look very nice, but I don't think we can diagnose it from that photo. There are two possibilities- one or more of the pins are not soldered, in which case remelting the solder and adding a bit with flux could fix it. They should be shiny and tapered up from the board (less shiny if you're using lead-free solder). The solder should not look like a ball sitting on top of the board if you look at it from the side, it should look like a volcano or a mesa coming up from the board surface. Some diagrams from this site:

Bad:

enter image description here

Good:

enter image description here

If you've damaged the board by scraping it with the iron or lifting a pad, then it will be harder to see, and fixing it would involve jumpering the header to some other place on the board. It's not impossible, but the fact it works when you wiggle the connector would tend to point to the first possibility.

After you've remelted it with some fresh solder, try cleaning the board with pure IPA (pure isopropanol, not low purity rubbing alcohol) and a (dedicated) toothbrush and it will be easier to see what is going on.

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