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Old 25th February 2005, 01:49 PM   #1
kita is offline kita  United Kingdom
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Join Date: Feb 2005
Location: cambridge
Default reverse engineering.... salvaged components

I was wondering if any posters or moderators had thought of complilling a list of salvageable parts from defunct consumer appliances. Of course we come across lots of references to caps pulled from televisions and motor psu's, pc psu's, but nothing comprehensive. While those who enjoy spending thousands on solid gold trannies probably aren't interested it definitely would be of use to rugged individualist diy'ers. And its of use to me as I'm trying to set up a charity which will reuse/recycle/resell some of the defunct compnents flooding out of my university...
So welcome would be:
-any thoughts on the project's viability. (BTW while I'm concerned about sound quality its not 'my' final priority, so be generous with what you think 'could' be useful)
-what 'consumer goods' might be included.
I've started with computer monitors, computer cpu's, televisions, fridges, bicycles (Al for heat sinks) but need more detail and 'insider knowledge of the guts of these things.
-suggestions for applications of said components.

It might be fun to do a diy audio competiton for the most ingenious steals and zero dollar builds, with 'listenability' being the bottom line of course. Could be very revealing
of audio possibilities all around us.

Thanks in advance- if this seems too lo-fi then any suggestions of people who might be interested then please let me know. But this is a diy forum....
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Old 25th February 2005, 02:41 PM   #2
Hugh M is offline Hugh M  Canada
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Join Date: Sep 2004
Location: Saint John NB
This seems like a good topic for a thread kita.
I have been stripping a bunch of old monitors of late and they are a good source of caps, diodes, resisters and other good parts. For any one on a budget, using these used parts means more money for active components and hardware.
The issue I have run into is identifying what the parts compostion is in the case of caps and resisters. I have searched the web and this forum extensively and have managed to answer most of my questions but it was very time consuming and there didn't seem to be a very good single source for type identification.
I was thinking that it would be helpfull to have a picture library of different types of parts, say caps, telling what thier composition is.
ie Are all of the dipped type caps some form of poly esther or does the colour of the dip mean they are composed of something different?
Perhaps there is a way to set this up in the Wiki pages?
Just some thoughts.
Lots of Fun and Good sound too - Who could ask for more?
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Old 25th February 2005, 05:24 PM   #3
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Join Date: Aug 2003
Location: Santa Cruz, California
This is an area where a bit of compromise and slight design modification can work wonders.

I was looking for a chassis, and not particularly wanting to mess about IEC punchouts, an already existing piece would gladden my lazy heart. Turned out the local second-hand stereo shop had an old Kenwood M2 sans power devices they were willing to part with for $35. When I got the thing home it turned out to have *exactly* the right power transformers for powering a raft of UcD180s. It still says Kenwood on the front, but at this point who cares?

Electronic surplus stores are also a great place to shop. I scored a linear power supply , +- 15 V at 1.5 amps with 1.5 millivolt ripple, for $20 in Denver. The transformer alone for a smaller supply would have cost me that much, let alone the other parts and the work to put them together. Much of my rig is made of surplus parts, and sonically they're _better_ than buying new because I can put the saved dosh into more music!

Salvage is lovely if you're willing to do a bit of impromptu engineering, or you can browse, jot down some interesting items, then figure out in the comfort of your home whether they really fit your needs.

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Old 26th February 2005, 03:57 AM   #4
Enzo is offline Enzo  United States
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Join Date: Sep 2004
Location: Lansing, Michigan
I recall the days 45-50 years ago when I would go behind the TV repair shops and find discarded TV chassis. I took them home and stripped them for parts.

These days among other things I repair video monitors - the kind used in arcade games. They are similar to computer monitors and TVs. I find that the most common repair is replacing a number of caps in them. The last thing I would use would be caps taken from dead chassis. The caps could well be why it was dead in the first place.

Also, I can buy nice new resistors for a penny each. Spend a dollar get a hundred. I find certain values used far more often than others, so they would be the ones to stock first. SO I can't imagine pulling a little 1k resistor off a board with its cut off leads and my labor.

But I do recall when I was full of labor and short of cash. And stuff like transformers and chassis and panel controls and stuff were great finds. I do still shop for surplus things to tear apart.

I not too long ago bought a Grass Labs Polygraph machine for $10. It was a whole five foot tall rack assembly on high quality 4-5" casters. Very nice for that alone. But the rack was full of rack panel modules, each an amplifier for the sensors, and each of those with a nice canned power tranny, various tubes, including gas regulators, very nice sealed pots and various nice knobs and readouts. What a bargain. Lots of swell junk and a great roll around rack for my shop.

Here is the tie in. I live near the local university. Michigan State Univ. and I got the thing and many other things from their salvage outlet. It is a large school - 45,000 students - with elec engineering, othre engineering, computer systems all over, physics departments, even a world class superconducting cyclotron lab. And the chemistry and microbiology labs are always getting updates for fine old things like pH meters with 6" analog meters on them. ANything any department no longer needs goes to the salvage outlet - nothing is thrown out.

They have a large area for computer stuff - and folks shop there a;l the time. ROws of printers, monitors, modems, peripherals, motherboards. Even a large bin full of power cords - 25 cents each. I can buy an old door or a student desk, or an old follow arc spotlight. I found a great old Tek scope there for $5!!! It was on the roll cart which sells for something like $250. My polygraph showed up. I go there and buy three-ring binders for storage of shop manuals. Three for a dollar, I just have to accept that they have things written on them like "Fiscal 1998-1999, crop loss expense reports"

Point being, that rather than parting stuff out yourself and hoping to sell the parts, you might consider setting up a salvage operation that sells the goods whole. If I find an old Xray machine control console, I can see it has a variac and great big knobs and maybe relays and power supply components, not to mention the housing itself. Frankly that is more interesting to me than fishing through loose parts.

If you pile parts out there, then will you be putting out tech info? How would I know what voltages a transformer produced?

If you had a dead microwave, what you think is of value might not be what I want from it. Or a stereo. You might gut the amplifier for the inner parts when what I want is the front panel to replace my damaged one.

You know what I find most useful in an old VCR? The large collection of metric screws. The AC mains cord is useful, I snip them off and save them. I might save the headphones jack if it is unusual. I have no use for the tuner, but that might be exactly what the next guy wants. But just put it on the table with $5 on it, and either one of us would buy it for our own reasons.

I bought a dead AMpex video tape recorder - 1" deck - for a few dollars. I didn't care a bit what was inside, I wanted its case. Retracting handles, removable lid, very nice enclosure for other gear.

I would be concerned that in trying to decide what parts of things someone might value, you overlook the willingness of the consumer to do it for you. Rather than have a pile of bicycle parts on the table - chain, tires, wheel, gears, forks, handlebars. Just hang the bent bike on the wall, sell it for a little and let the buyer take off it as he needs. That way you have zero labor invested in it.

There is growing concern over here about the high lead content in the computer monitor CRT glass, adn more and more places are requiring such equipment be recycled rather than tossed. SO there is potential there for heartache if you get involved. Look into that.

So that is my suggestion, sell the salvaged good whole. What would you pay for a resistor with clipped off and bent leads? ANd what amount of labor went into extracting the part.
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Old 26th February 2005, 07:26 AM   #5
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Join Date: Jun 2004
Location: Great Britain, South
Default Re: reverse engineering.... salvaged components

Originally posted by kita
I was wondering if any posters or moderators had thought of complilling a list of salvageable parts from defunct consumer appliances.
Someone after my own heart :-) I'm a great believer in salvage and re-use of parts - so dead equipment that can't be repaired or isn't worth repairing will be carefully taken apart for bits that can be re-used (I even rescue older audio kit from the local refuse tip, much of it turn out to be in working order) Aside from the environmental benefits (salvage being better than landfill, what I eventually discard is in bits so it's easy for the metal to be recycled) it's a cheap source of screws, fasteners, conectors, obsolete parts, vintage panel furniture (knobs), plus parts previously unknown and most useful :-)

I salvage large capacitors (electrolytics plus 240v main rated types), large power resistors, IEC sockets, fan, heat sinks, ferrites, rectifiers, big diodes etc out of PC power supplies (sharpens up de-soldering skills to!). Servers & disk raid arrays from HP & Sun contain top quality parts & connectors - the older computers are often better in this respect. Even the worst PC cases have mains rated on/off switch, fuse holders, fans, sometime even bits of light-pipe (for LEDs), and of course, plenty of screws and fasteners and lengths muticoloured wire and ribbon cables. Can't say I've found much use for old PC motherboards or network cards though! 72pin PC memory simms often fit older laser printers and some sound cards. SCSI disks and older-style memory simms are used in some older audio samplers.

Old disk drives and dead computer CD readers/burners are a good source of tiny little screws, miniture switches, various small motors/gears/rails/belts and miniature optical parts in the CDs. Compare the internal build quality of the cheapest high-speed computer CD with most consumer audio CD players - you might get a shock :-)

Hard disks have powerful magnets inside, and don't forget all those tiny jumpers from the pcbs. I've even re-used flexible 'printed' wiring looms out of older hard disks and printers.

Dead printers and scanners contain lots of useful mechanical parts, such as motors, stepper motors, gears, quality optical parts and various interesting fasteners.

Old cassette units/tape recorders can yield nice VU meters, knobs, connectors etc. Old audio kit (stuff that doesn't work and isn't worth repairing) is always good for connectors, knobs, pots (esp dual-gange volume control pots) and sometimes interesting switches. The really determined might hunt out RIAA pre-amp circuitry or obscure power FETs in old amplifiers/receivers :-)

Even horrible modern cheap audio gear can have useful surprises inside (but expect to have to break away "clip-together" constructions.) dead loudspeakers (however flimsy) will probably have crossover components inside, and maybe even decent connectors on the back. Old, heavy, large wooden loudspeaker boxes are worth refurbishing - with the right choice of updated drivers, you might save yourself making a whole new box. Some old drive units are even be repairable....

Even slow modems and old comms kit is worth a look inside - these often come in quality metal cases - and I've even found socketed ceramic logic chips inside!

Very old and broken test equipment may contain working valves, plus having high quality connectors and lovely vintage knobs - and any old analogue meters are always useful :-)

Haven't had any exeperience of true "white goods" (PC Monitors, TVs, VCRs, microwaves, washing machines etc) but I've a friend who's building a Tesla Coil and he salvages transformers from microwave ovens to use!

Best ever no-cost salvaged items from refuse tip - pair of 1976 Tannoy Cheviot Dual Concentric loudspeakers - now repaired and sounding lovely. Similar vintage Luxman bipolar amp - this in working order!

tekno.mage : make do & mend
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Old 28th February 2005, 10:37 PM   #6
kita is offline kita  United Kingdom
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Default looks like this could go somewhere

what a brilliant response. interesting, inspiring, alot springs to mind- but I don't really have time to do it justice right now. The important things are-
I definitely support the move to a wiki format but not sure how to do this. Moderators, scrappers, anyone interested? The main issue is how to organize the information so that stuff gets added in sensible places. Too often you just a pile of stuff to wade through, so I think sub-divisions are pretty important to keep all the info accessible. I'll have a go at this later in the week by compilling whats already been posted.
I also wanted to give a little feedback. The suggestion of keeping things whole and letting buyers do their own selection seems sensible but space will inevitably become an issue. Additionaly I hope to have a small army of volunteer students to exploit so labour time would be quite cheap
I also agree that fishing out every teeny resistor isn't worthwhile but larger value components probaly are. The most ubiquitous being smoothing capacitors on almost all elctric motors. Any experiences with their extraction/ classification? I know that the massive range of manufacturers and part numbers makes 'classification' pretty difficult but a basic 'six points to look for and its worth it' guide? I've brought up these caps as an experiment to see if it focuses discussion on particular areas, which would make compilling a bit easier but I'm really not fussy.

I'm going to a large computer recycler whos local and does only corporate stuff on tuesday to pick up power supplies and hopefully some lcd monitor panels for a diy projector. I'll look out for good cases and whatotnot. Any requests- I live in Cambridge?

Whats great about Enzo's post is that the set up he describes for a large US state university is totally nonexistant in Cambridge or Oxford! Currently all solid wastes from the uni just gets landfillled- I've even seen mass spectrometers and lazers in the skips! Plenty of opportunities then... not sure how to incorporate them into amp design tho....will keep you posted
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Old 25th October 2008, 09:22 PM   #7
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Location: Near Gothenburg, the westcoast of Sweden
Enzo wrote
"You know what I find most useful in an old VCR? The large collection of metric screws"

Hmmm, Where I live I save the sometimes useful inch screws.
I think that the inch standard is on the way to extinct though ...

Old thread but anyway ... have an nice weekend.
Cheers// Ove
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Old 25th October 2008, 09:31 PM   #8
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When I find a dead or near dead receiver or amp at Goodwill I strip it and salvage parts, but none are more useful than the collection of small screws, washers and nuts that can be culled from these.
These are more valuable that the components sometimes.
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Old 25th October 2008, 09:41 PM   #9
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You mean you are starving metric screws ?

I use to say that the best Japan brought us was the metric acceptance in screws and measuring standards I am a fan of ISO 9000 standard. ( My work is my brainwash ....)
Cheers// Ove
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Old 25th October 2008, 09:42 PM   #10
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I have a different problem: I buy say a broken amp or get given a monitor to pull apart for parts. Then I open it up and find the repair work needed is very simple & cheap, so it becomes impossible to destroy a perfetly good unit just to pillage it for parts, and I end up with yet another working amp that I can't part with, and no place to put it!
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