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In a desoldering incident, my beautiful board ended up like this:

enter image description here

Other side:

enter image description here

The guy doing the desoldering says there is no chance this board is usable since he claims he ripped through the connection between the pad and the board. To me it looks like the pads have been ripped out.

Is this board usable? How can I safely find out? I wanted to make sure that I don’t damage my MCU board by connecting to it, as I don’t have much time left before my deadline to get replacements.

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    \$\begingroup\$ Rest In Peace (RIP) circuit board. If it's a multi-layer board, then almost certainly the board is ruined. If it's a two layer board, an experienced and trained electronics technician might be able to salvage the board by drilling out the existing plated through-holes and using a circuit board pad/trace repair kit to repair the pads. For example: youtu.be/GNBcNkP7qlM \$\endgroup\$ Mar 14, 2020 at 9:39
  • \$\begingroup\$ @JimFischer Any way I can safely know for sure? Should I just try soldering some headers and seeing if it works? \$\endgroup\$ Mar 14, 2020 at 9:42
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    \$\begingroup\$ Check if the pcb is double- or multi-layer from the data given in this page under "technical details". As Jim stated, if it's double layer then it can be repaired. \$\endgroup\$ Mar 14, 2020 at 9:45

3 Answers 3

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It is only a double sided board. You should be able to salvage this, though it will be ugly.

You cannot simply install a new pin header and go on. Many of the traces to the eyelets are broken - you will have to work around that.

You can see where each pin should be connected by looking at the top and bottom sides. You will find a trace that leads to each eyelet. Follow each trace to the next component, and solder a wire to that component.

Do that for all of the external connections on the board, then connect those wires as you would have connected the header pins.

When you check the connections to the pins, you might find a pin with more than one connection. In that case you must follow all of the connections to the next component. You must then connect all of those points with short pieces of wire.

The Adafruit page includes this link to the Eagle PCB design files. If you have Eagle (or can install the free version) then that will help in figuring out where to connect your wires.

What you'll want to do is to make a "breakout board" for your breakout board.

  • Solder in all the wires to replaces the pin connections and fix any connections between components that were broken by the destruction of the eyelets.
  • Use hot glue or epoxy or blue tack, or whatever you like to attach your breakout board to a piece of perfboard.
  • Solder all of the wires to a row of pads on the perfboard in some logical order (and make a labeled drawing of which wire carries which signal.)
  • Connect your other wires going to the rest of your circuit to the adjacent pad of the correct pins on your perfboard "breakout" and bridge the perfboard pads together.
  • Keep your wires as short as possible - the signals involved aren't extremely fast, but they probably have sharp edges that need to stay sharp.

It will not be neat, and you will have to be very careful to make sure you connect all pins properly.

Work slowly, be careful, be methodical.

It can be done, but it will not be easy.

Good luck.


  • You will need a fine tip for your soldering iron.
  • You will need a roll of thin solder (0.5mm rather than the 1mm and thicker that is so common.)
  • You will need a roll of thin wire (this kind of stuff.)
  • You will need a pair of tweezers to hold the wires while soldering.

From the look of it, you need some practice in soldering. You'll have to get the practice on your own, but maybe this will help you in figuring out what and how to practice.

Follow the steps in the order they are given in the table of contents. The earlier steps are basic things that you will rely on later.

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    \$\begingroup\$ that board is pretty cheap; buy a new one, invoice him. \$\endgroup\$ Mar 14, 2020 at 10:26
  • \$\begingroup\$ @MarcusMüller The problem is because of Coronavirus there is a supply chain disruption, and extended delays when it gets imported through customs (last time it was stuck for three weeks, without any reason given). I ordered new parts but no idea when it will arrive. In the mean time I have to make do with what I have or else I won't have anything to demonstrate for work. \$\endgroup\$ Mar 16, 2020 at 3:38
  • \$\begingroup\$ @JRE I've been removing the solder stuck in the pads using the "SLAP" technique, but small amounts of it are still stuck inside. To get it out I've been using a fine tip to insert in the holes and try to melt it. But consequently I've noticed some of the "print" on top turning black and something transparent melting. Am I damaging my boards by trying to "melt out" the solder with a fine tip? Will the soldering tip in the hole for longer periods damage the board because of the heat ? \$\endgroup\$ Mar 16, 2020 at 3:54
  • \$\begingroup\$ @JRE was also wondering what kind of wire you suggest, since this it seems like really fine connections and I need to avoid shorts. Do you have any link to what you would use ? I have some hard wire (it looks like a single metal piece, rather than braided copper wire). \$\endgroup\$ Mar 16, 2020 at 3:57
  • \$\begingroup\$ If after destroying one you gave him another one to destroy, that is understandable. But my patience would run out after that. If he continued destroying boards after the first two on his own then he is a fool. \$\endgroup\$
    – rew
    Mar 16, 2020 at 5:44
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Use lead based 60-40 wire solder.
Use a clean well tinned iron.
Iron should ideally be temperature controlled.
Clean iron tip by wiping on a clean rag or suitable sponge (some melt).
Material from 'jeans' works well. Tin iron tip before use - ie melt solder onto tip.
Place tip on point to be soldered and simultaneously feed in solder wire onto the track at the point where the iron touches. DO NOT hold the iron on too long - the track will peel.

Use the ADAfruit images and circuit diagrams to determine what SHOULD be connected to the pads. Here and Here and

Clear the damaged holes of solder.
Use solder-wick or a solder sucker if available.
If not, heat and run in MORE solder until hole full of solder THEn rapidly bang PCB on table etc - liquid solder will leave the PCB. Do not heat for longer than needed.

Pass copper wires through the holes from the undamaged side, terminated on pads related to the pad as found in the ADAFruit documentation.

Solder filling the holes MAY also help.

If the board does not work, use the ADAFruit circuit diagram to work out what is not connected.


Here are the top connections:

enter image description here

And here are the bottom ones.

enter image description here Most go to vias.
DO NOT DAMAGE THE VIAS.
Tracks can be CAREFULLY scraped clean of solder mask to allow soldering if necessary. Use a sharp scalpel blade or similar. Be careful and sensible and it should work.
May not be needed.


Top copper:

enter image description here

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  • \$\begingroup\$ @KaizerSozay Sorry - I had a correct diagram then used the wrong one. See my modified answer. The ADAfruit site has photos and schematics of your board. You can work out from these what the pads SHOULD connect to. You can use wires to connect the pads to a convenient component pad on the board. \$\endgroup\$
    – Russell McMahon
    Mar 14, 2020 at 10:21
  • \$\begingroup\$ Soldering advice can be given :-). Where are you located, if I may ask? \$\endgroup\$
    – Russell McMahon
    Mar 16, 2020 at 7:50
  • \$\begingroup\$ One more thing: Solder in the new header and THEN use a multimeter connectivity check and the schematics/board files to check for connectivity to where it is supposed to go. I'm guessing(hoping) you'll find that more than 50% is still there. So that would save you half the work in putting down those wires..... \$\endgroup\$
    – rew
    Mar 17, 2020 at 15:34
  • \$\begingroup\$ @KaizerSozay What rew says BUT if you solder in a new header the plastic spacer will cover the pins as they enter the board making it hard to solder to them if the track to them is broken. If you insert a VERY fine wire in each holes first - thin enough to allow header insertion as well - then you can take that to anywhere needed when the header is in place. || OR ... \$\endgroup\$
    – Russell McMahon
    Mar 18, 2020 at 6:32
  • \$\begingroup\$ ... Headers usually have long pins on one side and short pins on the other. Insert the header into the board long side first so the pintips just reach the far side. The spacer is now above the board surface. Solder. Now IF needed you can connect fine wires to the long side pins at the board surface. When finished the spacer can be pushed down to lengthen visible pin length, or removed. \$\endgroup\$
    – Russell McMahon
    Mar 18, 2020 at 6:32
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Psh doesn't matter the amount of layers the board has. It matters the experience. I can trance a signal through multi layered boards no problem and yes you can use the same pin hole just with a wire jumped to that pin or which ever pins are damaged. Almost anything is fixable if it's important enough.

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  • \$\begingroup\$ I’ve been struggling all day. Through in the towel, ordered new parts. \$\endgroup\$ Mar 15, 2020 at 15:12
  • \$\begingroup\$ @KaizerSozay DO NOT GIVE IN. This is almost certainly well within your capabilities. Use the ADAFruit documentation to work out where the pad connect to. In many cases you will be able to see PCB traces on the top or bottom of the board. | Solder bare pins or wires through the holes from side to side. | Use ohmmeter to see if pin connects to where documentation says it should. Where it does not, wrap 1 turn of wire around a pin and solder. Run wire to a pad that it should connect to but doesn't. Leave a little spare wire length & cut wire, remove insulation at end. Solder. Keep us informed. \$\endgroup\$
    – Russell McMahon
    Mar 16, 2020 at 3:32
  • \$\begingroup\$ A dozen. Wow. In that case. Can you take the best photos possible that show the tracks going to the pads (or what is left of them). Both sides. Also can you provide a link to the related ADAfruit docs. || How did somebody butcher 12+ boards in this manner? Life happens, but ... . \$\endgroup\$
    – Russell McMahon
    Mar 16, 2020 at 7:49
  • \$\begingroup\$ @KaizerSozay See additions to answer. That may be enough. \$\endgroup\$
    – Russell McMahon
    Mar 16, 2020 at 11:23
  • \$\begingroup\$ > Almost anything is fixable if it's important enough. I had a 1Gbyte flash chip that was broken in two. Assuming a perfectly horizontal or vertical break (it wasn't) that would mean at least 100000 wires were broken.... (but a multiple of that if there is more than one wire per column/row, which seems likely). Good luck with that one.... \$\endgroup\$
    – rew
    Mar 17, 2020 at 15:40

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