Salvaging electronic components from old electronics… Not worth it?

I’ve seen a few websites where other electronics hobbyists talk about where they get their parts from and many do what I did about 25 years ago; salvage components from scrap electronics by desoldering them. I must admit it’s something I do from time to time; when I throw out old electronics I see if there are any parts worth keeping but mostly there isn’t. Some people on those forums desolder capacitors and resistors for re-use; to me this just isn’t worth it considering the price of components nowadays. Also there is the problem that here in the UK and most EU countries it is illegal to take stuff from the dump or out of dumpsters. It is counted as stealing as once you dump something it becomes the property of the city council or waste company. Many companies smash up equipment before disposal to prevent reuse as well.

If I do salvage any parts they are what I have taken from something I have owned myself or have been given to repair and deemed BER. I usually salvage expensive IC’s or complete PCB assemblies that can be reused or repurposed. To me the only things worth keeping are LED / LCD displays (if they have a standard interface, if not don’t bother) microcontrollers that are in DIP format and are not locked, sensors and large value capacitors. The rest are not worth bothering with. 25 years ago I used to keep everything and when I went through my component drawers I still have a lot of them. Capacitors age and some of them were 40 years old and hence useless. Considering the price of new I chucked them all along with the countless desoldered resistors.

I kept some transistors as they always come in handy for projects especially if you just need a simple switch or LED driver but most were very old and obsolete. Things have come a long way since I started with electronics. Component suppliers were expensive; there was no ebay or Amazon to get cheap chinese parts. Nowadays you can buy anything online and often cheap so it’s not economical to reuse old parts.

To sum up things that are worth keeping;

LED display modules, character and graphic LCD modules that have standard interfaces that can be easily used in microcontroller projects. These are sometimes otherwise expensive to purchase in particular graphic VFD’s many of which have a standard interface. These types are mostly found in very old equipment as modern devices often use controllerless displays which are hard or impossible to use without the rest of the equipment. An example of this are the colour LCD modules used in HP all-in-one printers. Relays and large value capacitors are worth keeping too and mains input connectors and switches.

For those into robotics old laser printers can be a useful source of parts as they contain lots of motors and driver IC’s and in older models graphic LCD modules that can be reused. Some white goods such as dishwashers can contain useful things; a Bosch dishwasher contained a nice 240×64 pixel red backlight LCD and a 4 digit 7 segment display. Often microwaves use standard 7 segment displays that can be reused for that Arduino project.

Things that are not worth scavenging parts from are things like old TV’s both flat screen and old school CRT’s. Old VCR’s and set top boxes can contain useful LED displays but that is about it. The rest of the parts tend to be custom FPGA chips and other custom parts. As for microcontrollers I have only ever found one that was not locked so that it could not be reprogrammed. Most micros in electronic goods have the ‘fuses’ blown to prevent reprogramming and reading the code.

Anyway this has been a short ramble about my feelings about using old electronics for something. A lot of electronics engineers do not like waste but you have to draw the line somewhere. Feel free to comment if you wish.

3 Replies to “Salvaging electronic components from old electronics… Not worth it?”

  1. Actually, there *is* at least one nice salvageable part in old CRT TV’s: the high voltage transformer and/or voltage multiplier 🙂
    They also contain a bunch of heatsinks of odd shapes and sizes, as well as a whole lot of ferrite cored inductors and transformers.
    Do mind the tube, though – although the screen is very thick and sturdy, the neck is quite fragile and easily broken, and there’s a lot of stored energy due to the vacuum inside.

    Salvaged AVRs can be reprogrammed, even if locked – the “fuse bits” aren’t actually physically permanent on those; issuing a “chip erase” command also clears the programming lockout.
    Of course, if locked, then it still isn’t possible to download the existing code before erasing.

    Electrolytic capacitors age particularly quickly – generally not worth salvaging at all from any equipment older than a few years.
    Other types age much more slowly: ceramics and mica are the best in that regard, followed by foil/film and tantalum caps. I still have a whole bunch of ceramic caps half a century old, and they’re still good 🙂
    Paper caps, not too great – especially if it’s the ancient “tar-sealed glass tube” version! They slowly absorb moisture, and eventually develop an unacceptable leakage current.

    • Yeah I’ve salvaged a few heatsinks from old TV’s in the past . As for the CRT when I used to repair computer monitors we had to ‘neck’ the tube before scrapping. I found popping the small bead at the end of the neck worked best but the other engineers prefered a hammer straight through the neck.

      • Popping the bead is safest – in fact that’s the intended way of “safing” CRT’s.

        Regarding taking from garbage dumps – in Poland it’s very common to see homeless people (as well as local drunks), err, “recycling” the dumped garbage 🙂
        No one even bothers trying to do anything about it – it’d be like attempting to inflate a fishing net; totally hopeless.
        Somewhat surprisingly, these “recyclers” are actually beneficial to the environment – since what they can’t use themselves, they’ll invariably take to a scrapyard for recycling. Not only do they get paid for the scrap, but it also doesn’t uselessly end up in the landfill.

        But electronic waste – now that goes back to China, whence it came; and then it becomes someone else’s problem 🙂

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