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The worst imaginable thing you can think of happened. I've tried making a minor repair and it all rolled downhill like a snowball and now I have significant damage.

Extent of Damage

The pads got yanked out. I tried fixing them, but being that I'm relatively new to soldering I scorched the holes where the pads are suppose to be.

This has also ended horribly for the traces that connected to the pads tearing them off.

Here I have two pictures showing where the damage was done. (the red wire was my attempt at a fixing a trace. It worked sometimes, but ignore it. Its been deliberately cut off)

Here is the damaged trace. Because there was no pads or copper on the top side I used super-glue after the solder job was done.

Backside of the motherboard (little blurry). 16 volt capacitors for the display-screen. The circled area is in the middle of the 16 volt caps.

enter image description here

On the other side I used conductive wire glue as there was a spot where the copper was ripped off. It's hard to see, but you can see a black blur. This is the conductive wire glue.

enter image description here

I tried fixing the traces with conductive wire. It would work for a time and then it would stop altogether.

Question

What methods did you use when fixing significantly damaged vintage computers?

and

Should I really just stop by the electronics repair shop and have them fix it?

5

Preface:

So far it's hard to see anything on the pictures at all.

No offense, but from the descriptions it seams as if your skills are not up to the task. So having someone with sufficient knowledge handling it might be mandatory.

With thorn apart traces, 'wire glue' and 'super glue' attached it even sounds more than a simple repair job, needing an effort beyond just quite good soldering skills, as it may need reconstruction.

It may more effective to get yourself a new M100 (they are still cheap) and keep that one for spare parts.


Questions:

What methods did you use when fixing significantly damaged vintage computers?

With 40+ years of experience in soldering, my approach might not be usable to you. And even with that, there are quite some tasks where I nowadays ask younger colleagues to do the dirty job. Young hands without tools beat an old guy with a magnifying glass any day of the week :)

More important, it depends way more on the damage in question, so no generic answer can be given.

Should I really just stop by the electronics repair shop and have them fix it?

I'm not sure if a random 'electronics repair shop' is the best choice either. Also, their price might end up way above what a M100 is on eBay.


Now, if you really insist, and it seams as if, then please stop using stuff like glue, conducting paint, copper tape or alike, it'll all just make it worse.

[There are many ways to fix old boards, and some may be better under certain circumstances, but the one described in the following is usually the best generic approach]

Try this (*1):

  • first of all, get yourself an appropriate soldering iron.
    • Not more than 10W.
    • Or a regulated one.
  • Get some magnet wire
    • Size 0.15 or 0.18 mm might be right to start with, I'm using 0.1, but it needs experience.
    • Nowadays magnet wire is available in lots of colours
    • Use these colours to keep track of certain signals for larger patches.
  • Get a wiring pencil
  • Get solder
    • No, not the modern type, but good old fashioned led containing solder
    • This is important as the existing joints are made using such and they have different melting points, thus mixing badly
    • It doesnÄt need much solder as for most parts you'll be using the existing.
  • get a fine (scalpel like) knife
  • get a magnifying glass - mounted if possible.

Now a quite important intermediate step: Learn to solder fine joints

It may look easy, but it needs practice.

You need to get a feeling how long it takes until the solder melts, find the right timing when to add the solder to get the right temperature and when to remove the spool to avoid adding too much as well as to remove the iron at the right moment.

Back in apprenticeship they let us solder grids of 11x11 silver wires for about two weeks. It came to more than ten thousand joints done (and judged) before we were allowed to use it on real components :)

I don't expect you to go the same length, but try to do at least a hundret or so to get a very basic feeling about timing.

When you feel confident not to burn out even more of the M100, repair will work like this:

Cleaning:

  • Position the maginfying glass to see the area to be repaired
    • No, it doesn't matter if your eyes are still fine. You want to do a good job, so remove any chance to miss out on details.
  • Pick one trace to repair
  • Take the knife and cut away all damaged parts.
  • Now look for the first thruhole pin (or just thruhole) on either side
  • These two are to be connected using the magnet wire
    • Never connect anything on a trace. that's the best way to damage a board.
    • Always look for existing solder surfaces, most desirable existing pins.

Soldering a wire:

  • As usual start by 'wetting' (*1) the tip with solder
    • This also serves as a test if its up to temperature
    • Even if it's a temperature controlled one
    • It's important to do this at the earliest possible time to reduce wear on the tip.
  • Drop any access solder with the prepared wet sponge
  • Take the wiring pencil
  • Use a little drop of solder with the tip and use it to burn away the lacquer on the end of the magnet wire.
    • Not too much, just about 1-2 mm
    • With more experiance this step can be skipped, but for now it guarantees a better result.
  • Wipe off excess solder
  • Put the wire end against the first pin to connect
  • Press it with the soldering iron tip against the solder already existing
  • Wait until the solder melts and the wire gets embedded.
    • Not longer, this needs to be fast
  • Remove the tip, wait a second and test it's strength.
    • If it breaks away easy, the temperature wasn't right.
    • But usually it's hard to make it not right.
    • Just don't stay too long, there is no gain in frying chip or board.
  • Now look for the destination pin.
  • Take enough wire to move it there
  • Keep it loose, but not too loose.
  • A good measurement is if you could move the wire after being attached for about 10 mm sideways.
    • If the pin is long enough, try to wind it once around
    • If not, hold it against as with the last one.
    • Make sure to have it not too tight.
    • Solder it as before, using the existing solder
    • Add only a little solder if really necessary.
    • Again: Do not burn it - heating should be as short as needed.
    • Pull again to test the joint strength
    • This is not about proving your strength, just the joint.
    • Now hold the wire pin tight and wiggle to breake the wire.

Here it is, the first repair is done.

Repeat the cleaning and soldering until all damage is removed and replaced by shiny new connections.

These are only the very basics. There is much more to learn when doing repairs like this. So don't go over board. Don't hurry. One wire and one carve out at a time.

... Now someone has to convince me why a soldering 101 needs to be on RC.SE, when there's Electronics.SE?


*1 - I'm grateful for any help with english terms here

| improve this answer | |
  • I'm gonna try one more time with copper tape that has conductive adhesive. Maybe, I can carve out the trace from the copper tape. I'm to darn persistent – Travis Wells Dec 13 '19 at 14:57
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    @TravisWells Please don't that tape isn't meant to be used that way. it just adds problems on the long run. I'll ad a paragraph about magnet wire and how to handle it, if you really insist to continue. – Raffzahn Dec 13 '19 at 15:34
  • FYI, this method doesn't repair the PCB, it only gets the electronics working again. Google "pcb pad repair" for more information and how-to videos. – snips-n-snails Dec 13 '19 at 18:47
  • @snips-n-snails True. Then again, that's not only the most important part, as well as contemporary, but most important, it might be the most practicable, within the reach of the OP. After all, there is no gain by destroying the board even more. Don't you think so? – Raffzahn Dec 13 '19 at 19:18
  • I would disagree with your advice on a soldering iron. A 10W iron with no thermostat is likely to be cheap junk. A 60W thermostatically controller iron with a good quality interchangeable coated bits (including a needle-fine one) is a much better tool, and will also handle bigger scale jobs where a 10W iron would be useless. (And mine is now nearly 40 years old and still in perfect condition). But the OP seems to be blundering around cluelessly, which is 100% guaranteed to fail. – alephzero Dec 14 '19 at 0:13

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