I am considering buying a Hot Air System for practice at de soldering flatpack chips. There are some nice ones for sale on e bay for around the 60 pounds mark. Do any of you guys use these for removing Caps and other small single components . I have noticed the PCB trace is easy to damage by lifting component when small amount of solder is still there, on some boards , do you think a re work station could help in making neater less damaging repairs when pulling components.
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Re: Desoldering Caps With Hot Air.
Perhaps if traces are getting damaged then the iron isn't hot enough or the solder isn't fully melting.
I sometimes use hot air but you have to be careful you don't move small components with too higher an air speed.
Not sure if its a figure of speech but there should be no pulling of surface mount components, just a gentle lifting.Last edited by diif; 07-01-2015, 04:31 PM. -
Re: Desoldering Caps With Hot Air.
It's a good question - how best to de-solder smt electrolytic caps?
You have to heat up the long PCB pads, underneath the cap - so I don't see hot air working because the capacitor's body is in the way of the heat. I haven't tried hot air on a electrolytic yet.
Lately I use a soldering iron and a lot of heat. But still pads get ripped off.Comment
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Re: Desoldering Caps With Hot Air.
It depends if you want to reuse the capacitor or not.
If you don't care about it, easiest way to remove a capacitor is to gently twist the smt capacitor back and forth a few times until the wires break. Then, a drop of flux on pads and a tip with fresh solder will remove the old tabs that are still soldered to the tabs.
See the procedure explained here, at 10:35 : https://youtu.be/p1zhfYHUIIY?t=10m34s or this one at 5:50 : https://youtu.be/3-5UsS49170?t=5m53s
If you care about them, just flux the tabs, add solder to the tabs, then keep touching each tab for a second or so with your soldering iron... once both tabs are hot enough, a gentle nudge will move the capacitor away from that location
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You can desolder things with hot air gun, but imho hot air gun is best used for ceramic capacitors and resistors, or for small ICs in soic footprints or sot-223, dpak etc, stuff that has small pins. Wet the parts with flux (helps with heat transfer), use hot air gun, if needed drag a iron tip with fresh solder over the pins and you're basically ready to remove the part.Comment
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Re: Desoldering Caps With Hot Air.
Thanks for your advice people.Comment
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Re: Desoldering Caps With Hot Air.
trying to remove smd electrolytics without hot-tweezers is very hard and risky.
if you try to do one side at a time you lift pads, if you use air the cap explodes!!
i fucking hate those caps!Comment
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Re: Desoldering Caps With Hot Air.
Yeah, as STJ said, be careful! The caps can explode if you heat them up too much. Be sure to wear safety goggles.
-BenMuh-soggy-kneeComment
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Re: Desoldering Caps With Hot Air.
For SMD chip electrolytics, I just use two soldering irons as if they were a pair of hot tweezers. You need both hands,, but it works fine for me anyway."Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
-David VanHornComment
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I know I've been a little scarce lately (like the last 2-3 years), but I'm still here and still doing my thing with fixing PSUs.
For today's considerations, I have a Seasonic B12 BC-550 [A551bcafh] 550 Watt ATX power supply for you (click on links for full size images).
https://www.badcaps.net/filedata/fetch?id=3591771
https://www.badcaps.net/filedata/fetch?id=3591772
It's a modern ATX unit with fixed (non-modular) cables and an 80-plus bronze certificate. Here's the label:
https://www.badcaps.net/filedata/fetch?id=359177... -
Hello,
First, I am a complete noob with high voltage stuff. I'm learning, but I need help by someone looking over my shoulder.
I recently came into posession of a Heathkit IO-4205 5MHz Dual Trace Oscilloscope. The documentation is copyright 1978. I'm told it works.
I opened it up to check the caps before I applied power, and found the following black caps and wanted to know what they were. They are on the power supply board. I was able to read the name and model and came up with, "Nytronics 162J-1, 0.1uF, 20% tolerance, 2000VDC."
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Hello!
I have two projects on my work bench. One is a friends dead JBL Xtreme speaker with a blown voltage regulator and corresponding bulged and shorted cap. That cap has clear markings so I know what replacement I need for it.
The other project however is a whole different deal. It's a Zoom 9000 guitar effect from the 90th that has developed a devil hound howl when there is no input from the guitar. I'm guessing caps problem. So, since I don't really use this effect anymore I thought it would be a perfect project to learn on.
I have studied the board and... -
I'm trying to repair two old VCRs, they both have bad caps. One has leaky ones, the other would barely run until I subbed in some caps from another power supply I had laying around (though they are the wrong values). This vcr works for an hour or two, but then the power supply starts whining and the picture gets lines in it. I didn't replace all the secondary caps, so another voltage might still be problematic, or the values I used are too far off.
I've been on mouser and digikey but the options are a bit overwhelming. I just need some new ones that will work. They don't need to be top quality,... -
Good evening
I recently aquired a rev 1.1 Gigabyte 60XT, and was suprised of the amount of leaking caps for a motherboard of the P3 era. Especially the way the 330µf caps seems like the housing discolored even.
Now, there are some 3300µF 6.3V KZG series around the CPU. Would it be OK to replace them with something like EEUFR1A332 ? (Panasonic FR 3300µF 10V). Or was this board designed around very low ESR caps?
But I was also suprised about the bigger boys, which are 330µF 25V.
Could it be they used 25V caps because they were cheaper / available at that time?...
Comment