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I recently got my hands on some old electronics. After getting some to work and failing to get others to work, I decided to simply desolder some of the through-hole components to possibly use in future project.

After desoldering a few, I realized that resoldering them on to a new board would be difficult considering the tiny amount of remaining wire and that the quality was quite poor.

My Question: Is desoldering and salvaging through-hole and surface-mount PCB components viable, or should I just buy the components online?

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    \$\begingroup\$ It is definitely not worth your time, unless we're speaking of pricy ICs and such. \$\endgroup\$
    – Vladimir Cravero
    Commented Nov 10, 2015 at 22:11
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    \$\begingroup\$ My parents used to be SO embarrased that I would be found out going through the neighbors trash looking for old radios and such. We were poor and I couldn't afford even resistors from the local TV repair shop. We all gotta start somewhere. \$\endgroup\$
    – Marla
    Commented Nov 11, 2015 at 1:58
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    \$\begingroup\$ good to hear that @Daniel , I restore old radios, and sometimes it is difficult to find old germanium transistors. I know that technology is moving fast these days. But I think the heart and soul of learning IS fundamentally based upon the "where there is a will, there is a way." \$\endgroup\$
    – Marla
    Commented Nov 11, 2015 at 2:23
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    \$\begingroup\$ You should consider work needed to salvage the components ahead of time vs storing the dead devices and salvaging them as needed vs ordering new parts. Most people I know tend to store the boards if they expect to need parts from them and have storage space. This saves them time when a device is brought in for repair (vs ordering new components) and does not require any work. Cheap things, like Rs and Cs, may be pre-odrered and stored in some quantity if they are often required. \$\endgroup\$
    – Eugene Ryabtsev
    Commented Nov 11, 2015 at 7:49
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    \$\begingroup\$ Ask yourself: what money do you save by doing that, and if by doing something else you could not earn more money, buy the parts and keep the change. \$\endgroup\$
    – PlasmaHH
    Commented Nov 11, 2015 at 10:18

4 Answers 4

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I routinely salvage through-hole and even SMD parts, with the following considerations:

1) If the device is broken, the components from it are suspect; check everything. I have one of these which is invaluable (It tests more than transistors).

2) If the leads are not long enough to go into a breadboard, it's probably not worth it. I find that most transistors are OK, but resistors often are not. Capacitors and LEDs are a mixed bag; your mileage may vary. Leads tend to be longer on older devices.

3) Be careful of static and heat limitations so you don't destroy the part you're trying to salvage.

4) If it's an IC or other non-obvious part, take a moment to look up the data sheet before removing it; if you can't find the data sheet, there's no point in having the part, unless you will repair more of the device you're tossing.

If you get even a few components out of a piece of garbage, it is probably worth trying.

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    \$\begingroup\$ This is a good answer. As a side note, I'd put that trough hole electrolytic capacitors tend to lose their capacitance after some time, so if the device is old, they might not worth to take (well, at least, test them before mixing them with the known good ones). \$\endgroup\$
    – ricardomenzer
    Commented Nov 11, 2015 at 10:52
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    \$\begingroup\$ I agree absolutely with ricardomenzer; capacitors are like food and they spoil. If you use a component tester like I do when salvaging, it will tell you the ESR, which is usually indicative of its "freshness." If the ESR is too high, the component is garbage. A table of typical ESR values can be found at en.wikipedia.org/wiki/… \$\endgroup\$
    – Thagomizer
    Commented Nov 11, 2015 at 23:45
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The answer is a resounding yes or maybe.

Yes salvage what you are likely to use in some way for play, study or repairs and maybe don't keep stuff that you will never use.

I find that keeping a couple of old and a couple of contemporary PCBs of the sort that I am likely to work on or experiment with saves a LOT of time compared to ordering or shopping for the odd part that I want to try out. I have very rarely made use of salvaged parts for any kind of production run of more than 2 as it it plain too slow collecting multiples of anything on scrap boards or in the junk boxes.

SMD salvage is difficult to justify and though through hole is becoming scarcer it still has a place in robust electronics.

Also remember to sort the pulls so you can find them speedily when you are in need. Exotic parts are much more useful to pull as generics are easier to buy in assortment kits. Having 1200 resistors (US$10) on tap is much more fun that hunting for a desired value and not finding it.

However of much more value than the components when starting out with repair , design or hobby is the amount of learning you can gain from figuring out what the boards generally (and later more specifically) did and why designers did what they did which will teach you good skills. You will learn to tell which boards were well designed with a glance and pay attention to new tricks they have used and which boards are commodity junk that is a second (or more) generation copy and contains defects or errors that have been copied over badly without understanding what they are doing. Generally industry gets better electronics because they pay more because their equipment makes money, consumers shop by price so they get junk.

It is always fun to see huge mains isolation areas on part of a PCB and then have the mains switch traces routed around to the other side of the PCB alongside all the low voltage circuits with 1mm track spacing.

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    \$\begingroup\$ I can't agree more; taking apart old stuff is instructive for both good and bad examples of design choices, and very importantly, you get to practice soldering skills when it doesn't really matter if you destroy the board or part. \$\endgroup\$
    – Thagomizer
    Commented Nov 11, 2015 at 23:47
  • \$\begingroup\$ I have also found that If a board has a good selection of parts that have value it is often easier to leave them on the board. It keeps the parts in context and safe from loss or misplacement. It is easier to judge if a part could be a suitable placement if it is in a similar spot in a similar circuit board rather than lying loose in a mixed box. Space to store boards is a problem obviously. \$\endgroup\$
    – KalleMP
    Commented Nov 14, 2015 at 0:05
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For me, I would only salvage parts you'd need for a project you're working on now. Otherwise, you'll keep piling up components you'll never use, and space is precious.

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You can salvage THT components rather quickly if you fix the board in a vice on an edge and then pull off components with pliers while heating up the other side with a heat gun. Take it outside, though, you will create very smelly smoke if not well practiced in that technique.

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  • \$\begingroup\$ Using a small gas torch also works but the smell is more and the board is a stinking charrred mess when you are done. These methods only work if the component leads have not been tensioned or bent over. \$\endgroup\$
    – KalleMP
    Commented Nov 11, 2015 at 20:27

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