general question: mainboard caps

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I noticed that one of the capacitor leads is connected to what looks like a fat copper trace (ground?) The other lead seems soldered to just a tiny little circle... if I hadn't looked closely, I might have soldered it to ground by mistake too...

Yes I'm a beginner at this, and thanks!

I heard that the bulb doesn't work very well. My dad has one. And hey, I play the piano too! Trying to learn how to play George Winston's piano solos... The Cradle is pretty straightforward, but, oh man, his variations on the Carol of the Bells is extremely tough!

Michael

LOL! We had wood burners but I think I was only 10. I can't imagine the politics of selling those thing to children of that age as a child's toy these days.

Hi Michael!

Makes repair surely easier :). It's always my advice, but I don't have an desoldering-iron (vacuum) since then ;-). The 'right' stuff is expensive....

I have done some boards, desoldering the failing condensators by changing the soldering-iron from one pin to the other, pulling the capacitor side (pin) by side (pin), out of its placement. The new caps I pull into the same way.... Tin-solder I take only a tip..., just to have a better contact to the origin tin-solder of the mainboard, which can be tricky and sticky :-(.

Some boards are easier, and you can desolder it with desoldering-lace (flex, cord). Plus, that the standard (yours) tin-solder will be adopted, too.

I can't recall how old I was when I got the wood burner, so I guessed on the age. I may have been younger. Mine hand a huge ceramic heating element, with a diameter about the same as the handle. There was no way to put it down anywhere without seriously burning what it touched. The unplated tiny copper screw-in tip was a bad joke that pitted badly after a few hours of use. The handle got really hot. I had it for maybe 30 years and used it for cutting and welding plastic. By todays standards, the old woodburners are dangerous even for an adult.

Some of the traces and pads are VERY close to nearby grounds and other traces. Be careful and don't slop too much solder around when you install the replacement cap.

Steal the bulb, throw it away, and get him a solder sucker. Better yet, steal just the teflon tip. It fits some solder suckers.

I can't read a note of music and scribble my own. My playing is awful but given a few centuries practice, it might improve:

My Korg DDS-1 synthesizer slowly died over the last month and is scattered in pieces all over the living room. I can't tell what failed, but it's making strange noises and the LCD backlighting has quit. Yet another project. Playing music is the only thing that keeps me sane, which may explain this months rants on usenet.

That reminds me... is it a good idea or a bad idea to solder the new cap with normal (leaded) solder?

Thanks,

Michael

A good watered sponge does work. Good condition solder-tip expected...

So many Tips and Tricks you gave, I don't think Michael will understand the halve of it ;-)

Some people do have only one hit in their life, but. E.g. 'Scatman'. Or...!... 'Born to be Alive'!

With this in mind, play your melodies and enjoy the time. I do so...

Mainboards, AFAIK, are soldered in an solder bath. I don't know the temperature nor the solder-tin they use. Even that, I would have no idea what to do with the data ;-)

I do by trying. Believing my skills (can excel to rubbish quality, if I don't keep the pace regarding IT motherboards) might help.

But you can make some repairs if you dare, and save some money here and there. (I am starting to rhyme in english... :-))

Keep an eye, as other posters said (take a lens for example!), for solder- spots/patches/splotches, where they shouldn't be.

By the way. Power capacitors are, I would say, arranged to the bottom side of the mainboard. The pins of the cap goes through the board. I have had similar thoughts as you... 8layer, 4layer special electronic, but, so long as I have had bringing back PC's, I am pretty sure power caps are to be found on the bottom side (physically on the top side, off course).

Dad always used a sponge (repaired TVs and radios decades ago) for solder work. I prefer a used tissue personally. (A sponge is such a waste.)

Michael

Then why is the industry standard for manufacturing? They can be rinsed out and turned over. Even with heavy use, they have a long life. Also, it is much easier to keep them damp that a dirty kleenex. You do not want the sponge to be sopping wet, just damp enough to keep it from burning. If it is too wet it can cause the iron plating to crack, and cause the tip to have a very short life.

nd

What? There is still electronics manufacturing in the United States?

Yes, just not $10 radios or $20 TVs.

No. It's highly likely that the motherboard uses RoHS blessed unleaded solder. Mixing solder types results in a rather dull looking cold solder joint. However, if you suck away all of the solder on the pad, you can probably get away with switching solder types, but I wouldn't bother. Just get the right solder.

Incidentally, I have two soldering irons on my bench... one for each type of solder.

Will wonders never cease... ok, I'm taking half of my wife's dishwashing sponge then...

Michael

I'm with you on the braid but it _is_ good for cleaning surface mount pads before installing the new component. A Metcal with an STTC-126 tip is about the best if you _don't_ have a vacuum desoldering station. The small tip can fit partway into the hole after the component is out and then you can use an old fashioned solder sucker with excellent results.

G=B2

Is it a real sponge, or just a fake plastic version? Spend the couple bucks and by one treated for cleaning soldering iron tips.

Don't do that. It's probably a plastic immitation sponge. It will melt or burn nicely, even with sufficient water. The real soldering iron sponges are cellulose and cost about $1 online. You can find cellulose sponges at the market if you read the label carefully.

The other problem is that the household sponges are too thick. After a few minutes, the water will dribble back into the base of the sponge, leaving the top of the sponge quite dry and easy to burn. Too thin is also a problem as you don't want to submerge the soldering iron tip into a puddle of water. I'm too lazy to walk downstairs and measure the official Weller sponge thickness, but try to get it close. For a holder, I find glass ashtrays to be perfect.

Thanks to all for your expertise in de-soldering...there is a world of experience here, and worth much. I have never had luck with braided wire...but evidently is works for some. (I never have any luck with super-glue either!)