Step 4: Resistors

In contrast to capacitors, resistors are easy. They are usually white on the underside, black on top and have the value printed on them. The last digit is the number of zeroes. The first two or three digits are the figures before the zeroes. In ohms.

560 means fifty six ohms. 561 would be five hundred and sixty ohms. 564 would be five hundred and sixty Kilohms, or, more concisely, point five six Meg.

These are also seen as arrays, pictured here are 33 ohm arrays I soldered together because I did not find any use for them.

When kept loose in a box, they tend to obey Murphy's law and all of them will be hiding white side up. And the one you want will be the one you turn up last.

Because when you find the one you want you stop looking.
This the method to use when you need to extract just one component from a circuit board. It complements the "Bulk extraction" methods of using hot air or a toaster oven, because extracted components are a bit fiddly to handle and store for later use.
<p>Hey, thanks for the ideas. In return, I'll share one with you which I got while reading your instructable. In the picture where you've taped the resistors to the clear plastic, you mention peeling the tape back to get the ones you want when you need them. In stead of peeling the tape back, which the tape would eventually lose it's effectiveness and you're freeing ones you don't intend to; you could spread them out just a little when taping them the first time. After that, you could use an razor or sharp knife to slice free the one you are seeking at the time.</p><p>Thanks again for the great ideas for recovering smd items.</p>
<p>Wow! They are SOOOOOO tiny!</p>
try sticking the small resistors to a piece of elec. tape or duct tape right side up. no more hunting, when u want one jus use tweezers to get it off the tape. jus a lil tip, might help u guys.
IC's are such a waste. I wanted an led display and chip but you know the chip is impossible to figure out. just a waste. Ofcourse component makers don't want a used market undercutting them.
The main consumer of parts in not hobbyists anyway, but factories. The reason the ICs can be so difficult to work with is either because they are cheaper to make that way, or the particular pinout order was easier to connect to some other specific chip without crossing races or stuff.
What about sub-ohm resistance values?
isn't the one you want <em>always</em> going to be the one you turn over last? why would you keep looking after that? jk ;D<br/>
So that you can find the one you don't want.
Just google search &quot;capacitance markings&quot; for more tables than you could ever possibly need.
To find more information about coding SMD-components read the book <strong>Turuta E., Turuta M. C. SMD-codes. Active SMD semiconductor components marking codes</strong>.<br> And then you can download apropriate datasheet from&nbsp;&nbsp;<strong>http://www.datasheet4u.com</strong><br> I use thise steps and save a lot of money while making a lot of gadjets from old electronics!&nbsp;
I'm interested in salvaging ICs and whatever I can for educational projects, however, which parts are worth saving. The ICs seem like a no-brainer (at least the ones that have datasheets) but what about other components? I think I read somewhere that some SMD components are not worth salvaging due to lack of information on them (no datasheets or info). Could any knowledgeable individuals chime in on this?
so how do you remove those IC's with 5000 pins?
You can use a paint stripping heat-gun if you don't have access to a solder reflow workstation. It worked fine for me until I got mine a few months ago :)
what about a toaster oven, i have removed components off a board with one (accidentally) but it is reliable? and what it a solder reflow workstation?
sorry for very delayed response,<br>its a hot air gun for working with surface mount components.
A correction needs to be made in your Instructable.<br>A 564 resistor is actually 560,000 ohms(560 Kohms) and NOT &quot;five hundred and sixty thousand Kilohms&quot;.<br>
Edited to &quot;560 Kilohms&quot;. <br> <br>Thanks.
I <em>hate</em> removing SMT parts! <br/><br/>Nice instructable though... I like your method. You might also try making one of these:<br/><br/><a rel="nofollow" href="http://www.engadget.com/2006/03/07/how-to-make-a-surface-mount-soldering-iron/">http://www.engadget.com/2006/03/07/how-to-make-a-surface-mount-soldering-iron/</a><br/><a rel="nofollow" href="http://www.gideontech.com/content/articles/297/1">http://www.gideontech.com/content/articles/297/1</a><br/><a rel="nofollow" href="http://www.usbmicro.com/odn/documents/ACC430664DD26DDE5986574AAA62775FDFF29EA1.html">http://www.usbmicro.com/odn/documents/ACC430664DD26DDE5986574AAA62775FDFF29EA1.html</a><br/><br/>You could also try using a clothes iron, like in this video:<br/><br/><a rel="nofollow" href="http://video.google.com/videoplay?docid=-5064927163860056532">http://video.google.com/videoplay?docid=-5064927163860056532</a> <br/>
The Iron Is Genius!<br>
thanks for the clothes iron video! i just have a crappy soldering iron and i think the clothes iron trick will do nicely!
That clothes iron video is amazing. Thanks for sharing it.<br />
I love you. Good work.<br>
ive found a partially successful way to remove SMD leds with no chance of melting them and a small chance of breaking/losing them is not with a soldering iron, but a small exacto knife.<br><br>just slce under the LED and it will slide off the board with the knife, but dont put too much pressure on the knife or else you will either hurt yourself, other components on the board, or the surface you are working on.<br><br>i used this technique and out of 14 blue leds from a cell phone board, i got 10.<br>the other 4 were lost among the floor that happens to match their color.<br><br>i lost a few while learning to solder them, but it was a learning experience for getting them off, and it does wirk with patience.<br><br>i usually store my smd components in a small plastic bag (like you get those perfboards in @ radioshack), but a better storage method will have to be in order since the bag has a few holes in it.
The easiest way is to lock the board on a vice. Use a heat gun at high speed on the backside. Slowly remove the components with tweezer or needle nose pliers. Store components on an aluminum surface to cool fast. 99% of the components are good and reusable. Use google to look up datsheets for IC's. Then organize components by type and size. I can strip a motherboard in 3 minutes this way.
how to do leds??? wont it melt from the heat?
aha! so that is an old harddrive board!
&quot;so that is an old <em>fujitsu</em> harddrive board!&quot;<br/>
ahh... i have 2 dead fujitsus, they were very good quality if you ask&nbsp; me...
nicde. marx generator
-big pot -cooking oil -stove -scooping net thing. put pot on stove add oil turn on stove when it it super hot throw in your pcb. stuff will melt off. IC are made to withstand hightemperatures. solder will melt before there is damage to the IC. scoop out IC with skimmer thing. party on.
Are there any noxious fumes from doing this? Will I still be able to get regular resistors from this or willt hey melt? Will anything bad melt? Do an instructable on this please!
plastics might melt
I'm so proud of myself, I desoldered some 8 pin SOIC's with a $16 40 watt soldering iron! They didn't even melt(I lifted half the pad on a couple pins, though)! My iron has a nice tiny tip, and i keep it cleen. That helped a lot!
wow... i thought the brown capacitors were resistors, and the capacitors with stripes were diodes
Awesome! Great method for desoldering them! I may use this sometime.
Excellent! I bought a few SMD LED laden gift cards for a $1.50. I figured at a dozen leds per card it was worth seeing if I could harvest them off the pcbs. Now I know how! Gracias!
I do thr same as a hobby and keep the bad stuff out of the landfills..It also makes good art stuff..
check this link for storage<br/><br/><a rel="nofollow" href="http://www.engineeringlab.com/supkiten.html">http://www.engineeringlab.com/supkiten.html</a><br/><br/>or you can do it on the cheap like me and get those small plastic coin holders for dimes....<br/>
This is a great technique. Complements the hot-air stripper gun method perfectly. (Like, when you really just want one piece out of a given area.) Thanks.
Trust me on this get a cheap 15-25 dollar butane torch/soldering iron and if your desoldering parts i recommend getting good butane and just keep the torch constantly moving and the solder will easily melt Just get it anywhere but radioshack their torch's fuel tank is way too small i got a bernzomatic for 15 dollars totally worth it
Ya'know, I just use a toaster oven, wipe 'em all of when the solders hot then sort it all out. I realy like you storage idea with the sticky tape.
This is awesome for those cheap bastards like me who can't afford a heat gun. This is great. Thank you.
Yes, it would be easier to use a heat gun - if I had one. I pulled the IC before all the joints were fully melted and this was the result. It still works, it is a 74HC04, date code 8809. I should wire it up into something, just to show it off.
I was about to say something about you breaking the IC. But if you notice, you hadn't goten to the circuit yet.
I have an article and some pages devoted to heat gun scrounging. The following link leads to a How-To and FAQ section and a post about scrounging a rack mount router.<br/><br/><a rel="nofollow" href="http://www.uchobby.com/index.php/scrounging/">http://www.uchobby.com/index.php/scrounging/</a><br/>
After you try it you will kick your self how easy it is to remove even the most complex SMC bit. The trick is to use a chisel to work the components pins loose of the solder. any SHARP small chisel will provide just enough force on the solder to BREAK the joint. Use the flat side to the PCB and angle as low as is convenient to force the chisel at the base of the solder joint. just gentle pressure is usually enough to crack the part loose. If you can hold the chisel totally flat you can even remove the real large chips without damage from a botched solder attempt.. if you go after a large chip or other ESD sensitive bit i would recommend using a grounding clip on the chisel. As i said you will love this method to build the really small tek.
Great instructions and a sense of humour to boot! Thanks for sharing it with us.

About This Instructable




Bio: Hi. I'm Chandra Sekhar, and I live at the southern tip of the Indian subcontinent. I'm interested in building small one-off circuits around ... More »
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