How to professionally repair lifted traces

[Tone Meister]

I have a power supply circuit board from a GK700RB that took quite a hit. Two traces are lifted and need repair and it'll need proper insulation. There is NO charring on the PCB, just enough over-current to compromise the traces.

What material do you pros replace the copper with and what is the pro way to insulate the work area?

[Jazz P Bass]

Wire.

I try to match the trace to whatever I use to repair it.

Doesn't make sense to use 12 ga solid copper to fix a small signal trace.

[Tone Meister]

Wire.

I try to match the trace to whatever I use to repair it.

Doesn't make sense to use 12 ga solid copper to fix a small signal trace.

Easy enough. How about insulating the new work?

[The Dude]

If it's a long run, I'll leave the insulation and strip the ends to solder. If it's short and doesn't have to jumper any other traces, just use bare wire. There's really no need to insulate other than keeping it from touching something else- no different than soldered in jumpers that are designed into some boards or longer component leads.

[Enzo]

Agree with above. The original copper was not insulated, I only leave insulation on wire if there is danger of the wire moving to touch something.

Cut away any lifted copper. Do not yield to the temptation to "save" it.

The wires do not need to be huge.

[Tone Meister]

Alright, I'm tracking. In fact the repairs are already done. Can I at least save the cut away copper in a jar somewhere?

[g1]

If it's done, then this is too late, but I'll offer it up for next time, or it may be how you did it.
For both those traces, I would replace the whole length, using the pins or components at the ends to anchor.
In the first pic, by the big bridge, it looks like the trace is going from connector to connector. If so, I would put the wire on the other side of the board, going from pin of one connector to pin of the other.
Tack the wire down at least in the middle with your particular goop of choice.

[g1]

Alright, I'm tracking. In fact the repairs are already done. Can I at least save the cut away copper in a jar somewhere?

You don't send them in for biopsy?

[Mick Bailey]

I use wire, too. At one time I had adhesives and materials to replace the trace on the board, as well as pads and vias. It was a very expensive setup and really only suitable for shops that did that kind of thing all day long. Two drawbacks - the opened adhesive went off, and out of the set I used up one type of track more than everything else. It made for invisible mends, though.

For pads I now have some small eyelets - about 1mm or so bore - that I use where a pad has lifted. I also have some with a tag, so a good job can be made of wiring up between two locations. For complex repairs or where there's a hole I will etch a new section and bridge this in. Depends on the value of the amp/equipment and how much the overall job is worth.

You can cut new copper tracks from shim stock, but need to find the correct adhesive that will withstand soldering temperatures.

[Randall]

I keep a little box of clipped resistor or capacitor leads of various lengths and gauges for short run repairs.

[tedmich]

if you do find yourself with a jar full of (clean!) copper bits you could add some silver nitrate solution...



a little spendy at ~$1/g for the solid on Amazon/Ebay but its very water soluble, the copper (II) nitrate formed is a pretty blue green and less toxic than the starting compound. The silver metal can be in beautiful crystals



the copper sadly goes away...

[J M Fahey]

I use wire, too. At one time I had adhesives and materials to replace the trace on the board, as well as pads and vias. It was a very expensive setup and really only suitable for shops that did that kind of thing all day long. Two drawbacks - the opened adhesive went off, and out of the set I used up one type of track more than everything else. It made for invisible mends, though.

For pads I now have some small eyelets - about 1mm or so bore - that I use where a pad has lifted. I also have some with a tag, so a good job can be made of wiring up between two locations. For complex repairs or where there's a hole I will etch a new section and bridge this in. Depends on the value of the amp/equipment and how much the overall job is worth.

You can cut new copper tracks from shim stock, but need to find the correct adhesive that will withstand soldering temperatures.

Plain epoxy

But .... but ..... Epoxy does not fully stand molten solder temperatures !!!!!

Neither does the original PCB ... which by the way is Epoxy too

And thatīs why the Pad/trace lifted in the first place ..... and tracks lift on overheating .

Epoxy (and Phenolic adhesive in cheaper PCBs) does not stand soldering temperatures at all, even less if under *small* force applied to it (thatīs why juggling/twisting parts during removal guarantees pad lifting) but does so for , say, 10 to 20 seconds, ample for good soldering technique, not enough for tyros and hackers.

Personally I often reglue lifted pads and tracks with a little epoxy ... after scratching carbon of course.

[Tone Meister]

If it's done, then this is too late, but I'll offer it up for next time, or it may be how you did it.
For both those traces, I would replace the whole length, using the pins or components at the ends to anchor.
In the first pic, by the big bridge, it looks like the trace is going from connector to connector. If so, I would put the wire on the other side of the board, going from pin of one connector to pin of the other.
Tack the wire down at least in the middle with your particular goop of choice.

Yep G1, that is exactly what I did, run wires from pin to pin. I then clipped out any of the old copper I could get to from the old traces.

Thanks everybody, and sorry for the late reply

[nevetslab]

when you removed the filter cap's by the bridge to get at the foil damage, did any of the plate-thru copper come out still bonded to the snap-in cap leads? That often happens during the surgery, resulting in no more continuity between the top side and bottom side of that pad's trace, and requires additional jumpering to restore the circuit. GK tends to cut their component leads really close to the PCB, making it really difficult to remove tight-tolerance leads from their pads, without the pad delaminating from the PCB surface.