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Reduce, Re-use, Recycle! Answered

Lately I've been taking my spare time and using it to sit down (or sometimes stand) and desolder stuff from circuit boards. Just from one old computer motherboard that no longer works, you can harvest quite a few fully functional capacitors.

For my example I'll post a couple pictures I took a while ago, one is a pile of parts beside my keyboard from an old motherboard I nearly completely stripped except for the sockets and other things I didn't need or didn't have the patience for.

Tonight I found 4 more things to strip down, 2 mini power supplies (one from an old xbox, one from a junk tv set top box) and two toasted subwoofer amplifiers (no I don't plan on harvesting the transistors from them).

I find it completely wasteful to see all the electronics that go into the landfill, simply because it broke, and from experience a lot of electrical failures are usually limited to one or two parts shorted out or gone bad (although this is not always the case). So this is my little "effort" to help save the planet. Does anyone think I could sell bulk "used" capacitors/resistors/diodes in say, mystery bags with random types of capacitors/resistors/diodes? I'm also doing this for my own personal sanity as I have gone to fix several motherboards in the past that simply required a bad capacitor to be replaced, woopy do, but it does no good if I can't find any parts in my parts bins!

What do you guys think!? Also, would someone be willing to help me (maybe through msn would be easiest) identify certain parts I've found that I'm not entirely sure what they do or they're lacking of any useful numbers on them????

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lemonie (author)2010-03-27

I do this too, mixed bags you may be able to shift. Note that there's probably a market for Joule-Thief kits: ferrite toroid, transistor etc. in a bag. Also voltage regulator bags.

L

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Punkguyta (author)lemonie2010-03-30

 Oh sweet idea lemonie, tell me more in PM, the joule theif idea actually sounds swell to me, I should put kits of something together.

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lemonie (author)Punkguyta2010-03-30

Well, I've been stripping old electricals for years. I've not done too much with the bits, but I'm in the same situation as you are.

L

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Punkguyta (author)lemonie2010-03-31

 Yeah but then, is it just a waste of time to do said stripping?

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lemonie (author)Punkguyta2010-03-31

I've done things with 'em, I just have a large inventory at the moment.
Hence this question.

L

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Punkguyta (author)lemonie2010-03-31

 Holy.. And all I wanted to do was build some simple solar charging circuits and little things to monkey around with.

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gmoon (author)2010-03-30

Ever tried the "torch technique" for desoldering?

Heat the backside of the pcb quickly with a propane torch (or a butane "pencil" torch), then whack the board on the floor to dislodge the components.

It's usually so fast that very little heat gets transferred to the ICs. A soldering iron just takes too long for a large DIP, and tends to heat it up too far.. You can do it on a small area, too--like a single IC, with the pencil torch. I've had about a 90% success rate doing this...

Doesn't work so well with bent lead components unless you use pliers or vicegrips.

You can use a decent heat gun, too.

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Punkguyta (author)gmoon2010-03-31

 I've wondered about that method, and then maybe also the possibility of attaching it to an old subwoofer or something to "shake" the parts out.

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gmoon (author)Punkguyta2010-03-31

I don't know if that would work; slapping the board is kinda "directional." The more mass each part has, the better it works.

But it has the potential of at least being a spectacular failure if it doesn't work.

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dboone628 (author)2010-03-26

I see two photocouplers (opto-isolators) in picture 7. They might be useful.

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Punkguyta (author)dboone6282010-03-30

 could you possibly point out what components you're looking at???

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NachoMahma (author)Punkguyta2010-03-30

.  They are the two four-legged DIPs on the right side of the pic. Just to the right of your comment box.

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dboone628 (author)NachoMahma2010-03-30

 Yes, thank you NachoMahma.

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Goodhart (author)2010-03-30
The biggest problem I have run into is the needed heat:  that is, if they are parts that are parts that are either surface mount or through hole, but soldered on the one side only, they are not too hard to remove without too much damage (transistors, optocouplers, some LED's, and many MANY ic's; are all subject to being overheated when soldering, much less reheating them and desoldering).  

Through hole soldering, with solder on both sides or a lot of solder on the "opposite side" from the component, can be a problem too. So much heat is needed to get them out, and if they are "close" to the board, it is hard to next to impossible to get a heat  sink in there to help.   I have a box of desoldered IC's, but I don't use them for new projects, because of the high failure rate.
 

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caitlinsdad (author)2010-03-26

 I thought that was cleaning out the junk candy drawer.  Some old tootsie rolls, peppermints, jolly ranchers...

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Punkguyta (author)caitlinsdad2010-03-26

 :p I like Jolly Ranchers

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Punkguyta (author)2010-03-26

 By the way guys, I'll post more pictures soon, I plan to do some more desoldering tonight.

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