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I am fairly new to working on electronics and need some advice with fixing a circuit board for my pops. I know this is not a chit chat site, so here goes:

  1. I located a broken trace from what appears to be a ground terminal (# 1) that runs underneath another component (# 2) next to it.

Components

  1. As I started to de-solder the component (# 3) by heating the existing solder and applying a small amount of new lead solder, I managed to clear out most of the pins with a de-soldering plunger, except pin # 5 would not budge.

De-solder Pins

I tried to add more solder to the pin and this time the solder went through the hole and underneath the component (# 4).Solder under component

  1. I read that you may be able to use solder wick to remove the excess solder underneath but I wanted to get some advice before proceeding.

I believe my biggest issue was using an outdated soldering gun from my pops and I have already ordered a new soldering station.

Mike D.

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  • \$\begingroup\$ You lost the pad with the pin 3?? Then you need to heat up the pin, #3. On the top side, heat up the pin, using any soldering iron, while pulling the connector out. You may need add solder on the pin, so it can take the heat. Solderweak or Soldersucker won't work. Next time, try to pull out the connector at once: First make a solder puddle (like solder bath) using solderweak and enough solder, right on the top of the connector pins. When all the pins are loose, pop out the connector, flip the PCB and tap on a wet kitchen towel to remove the solder at once. \$\endgroup\$
    – jay
    Commented Nov 4, 2021 at 16:02
  • \$\begingroup\$ Olden days, people made an emergency small solder-bath using aluminum foil on the top of a lab alcohol burner. \$\endgroup\$
    – jay
    Commented Nov 4, 2021 at 16:10
  • \$\begingroup\$ @jay I assume you meant solder wick, rather than solderweak? \$\endgroup\$
    – Andrew Morton
    Commented Nov 4, 2021 at 16:29
  • \$\begingroup\$ @AndrewMorton, thanks. :) \$\endgroup\$
    – jay
    Commented Nov 4, 2021 at 18:47
  • \$\begingroup\$ you should not place the PCB on a carpet ... that is only asking for ESD damage to the board \$\endgroup\$
    – jsotola
    Commented Nov 4, 2021 at 21:28

4 Answers 4

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I believe my biggest issue was using an outdated soldering gun from my pops and I have already ordered a new soldering station.

It's not. Desoldering multiple pins is a pain without specific tools. It's one of the tougher things to do. I have a wide blade tip to heat up all the pins at once remove through hole components, then clean up the pads and holes after. It's a crapshoot otherwise. Even if it looks like you cleared the solder from all the pins, it probably still won't fall out. Therefore, I would not worry about cleaning up that until the component is out.

Get a big ass or wide tip so you can heat as many pins as possible, as fast as possible and move around fast enough so all the solder stays molten and pull it out. Only clean up if the excess solder while the component is on the board if it is getting in the way of this process,

Alternatively, find a matching connector on Mouser or Digikey and just cut the connector off the board at the leads, and unsolder the pins and clean up the pads/holes one by one. It looks like a fairly common connector. Just make sure pitch spacing and the shroud match. This method is safest if you do not have a tip that can hit all the pins at once.

All that said, if you know a trace is broken and where it needs to connect, just connect it elsewhere and bypass the break. No need to reconnect it right where it is broken.

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Why are you trying to remove that connector at all? The easiest way to fix a broken trace is to solder a thin wire between the components that should be connected, but aren't.

It looks like you have completely removed one of the pads that the connector soldered on to. If so, then you're going to have to repair that too. Again, the easiest way is with a small wire.

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  • \$\begingroup\$ Simon, When I examined the circuit board with a medium magnifying glass, I traced the broken line from the ground terminal (# 1) to the left edge of component (# 2) next to it. I noticed the line was raised off the board and based on my research, you should not add a jumper to a lifted trace. Upon tracking the wire further, I realized the lifted wire continued under component (#2) and figured that is where I need to place the jumper wire at. Also, thank you for addressing the pad issue and providing a resolution. I was going to ask about that later in another post. \$\endgroup\$
    – Mike_D.
    Commented Nov 5, 2021 at 15:10
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For future reference - what you should perhaps have been doing instead:

  • Try to figure out why there is a broken trace to begin with. Was it damaged through rough handling or by over-current? In case of the latter, the broken trace is likely just a symptom and not the cause. You could have a short elsewhere on the board and several components might be damaged.
  • Desolder the TO-220 component at #1. If you have reason to believe there's been over-current/voltage issues, you might want to replace it. This is likely to be either a voltage regulator, a BJT or a MOSFET. In either case, something that likely deals with relatively high currents.
  • Make sure that the damaged trace/via isn't shorting anything else - cut off any protuding copper with a scalpel.
  • Connect the the leg of the TO-220 from the damaged trace/via and connect it with an isolated wire - not thinner than ~AWG24-26, it likely needs to handle a bit of current - to a suitable place on the PCB where the trace used to go. Either around the damaged area, or somewhere where you can scratch off the solder mask with a scalpel, or another through-hole pin like on this other connector.
  • Make sure that this wire is following the board surface as tightly as possible. Secure it with hot glue after soldering, if needed.
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  • \$\begingroup\$ Ludin, Thank you for the suggestion and you are absolutely right about trying to find what caused the power failure. This board sits in a loose compartment within my dads old trailer and we believe it shorted out during a bumping camping trip. I will remove the other component as well. As far as testing the board for things that may have caused the power failure, is there anything else to try besides visually inspecting, testing with multi-meter, etc? Sorry about my formatting, I cannot figure it out (I am still trying to learn more about this site.) \$\endgroup\$
    – Mike_D.
    Commented Nov 5, 2021 at 15:34
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To desolder this connector or any component with many pins in a row if you don't have a superwide tip:

Cut a length of 1.5mm2 copper wire long enough to span all the pins.

Place wire on pins.

Heat wire with soldering iron and add solder. (>60W soldering iron recommended).

Heat will travel along copper wire and heat all the pins at the same time.

Pull on connector.

Cleanup with desoldering pump.

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