Eh. This was the soldering job in a commercially-sold SMPS bench power supply from an Amazon.com reseller, IIRC, this was how it looked when it left the mfgr, I took this photo immediately after opening the enclosure and pulling the PCB (it had stopped working! can you believe it)
I'm using 400 grit wet/dry sandpaper for removing enamel. No reason other than it seems to last longer than the finer grits and I have a fair number of sheets. For very thin magnet wire or litz wire, I use finer sandpaper. If I want to scrape off the insulation, I use a moderately dull edge kitchen knife that won't cut or gouge the copper wire. If I try to solder magnet wire that still has some coating on the wire and was not tinned, I get a black carbonized blobs, like in the photo.
I have one of those. It's a counterfeit clone and is not made by Hakko. This is what the real FG-100 looks like: Note the price. I haven't bothered to verify the calibration on mine, but it seems to indicate what I would expect.
-- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
Eek! I'd like to see some insulator other than air between the AC nodes of that bridge rectifier, it doesn't look like the gap is very much at all.
-- Notsodium is mined on the banks of denial.
This is pretty bad. The box doesn't work.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
There's your problem. 15 watts is far too small for the heavy gauge wire you're using. The pointed tip is too small to retain enough heat to solder some of the larger parts in your photos. You also didn't bother to disclose whether you're using a temperature controlled soldering iron or a crappy wood burner. I'll guess(tm) a wood burner, probably with unplated rusted iron tips that can't be cleaned, wetted, or tinned.
If my guess(tm) is correct, you don't have a prayer making a decent solder connection even with a keen hand and a steady eye. The trick to soldering is to use decent equipment, a clean tinned tip, and the correct temperature. Use a hot tip set to the temperature for the type of solder you're using. Get the work hot quickly, solder quickly, and remove the iron as soon as possible. If you use a stone cold 15 watt iron, you'll end up lingering on the joint for far too long, which will dramatically increase the size of the heat affected zone, which will likely burn the PCB, vaporize the flux before it's needed, and possibly run some parts. By fast, I mean something like 1 second or less.
A friend of mine lived long enough to get Parkinsons Disease. Near the end, his hands shook bad enough that soldering was impossible. However, before that, they were steady enough to hold the iron, but not the work (wire and components). So, he build a fixture with an articulated battery terminal clamp to hold the joint together while he soldered it. For the soldering iron, he build something similar that only required that he leaned on the iron to push it into the connection. The process wasn't graceful, but it worked.
If you have vision problems, get a proper magnifier or microscope. My eyesight is becoming bad enough that I need to use a microscope for SMD work, and a magnifier for ordinary work. Good lighting also helps. My soldering would look as bad as yours if I didn't have these aids.
If you're not sure that decent soldering equipment will improve your miserable soldering, then borrow someone's decent equipment and try it for a day or three. If it's hopeless, look into the possibilities of using a soldering robot: (1:33)
I had problems finding can type electrolytics so I used axial leaded electrolytics as a substitute. They fit inside the old can, so I just ripped out the guts from the defective capacitor and crammed the axial caps inside. I used 85C caps which lasted about 6 months. I replace them with 105C caps and they've been running for about 2 years.
If you know it's not going to work, why bother doing it? You're not going to get a decent solder connection if it's covered with melted or burnt insulation, no matter how nice your tools or technique. A decent solder connection requires that ALL the parts of the puzzle are clean before you apply heat and solder. Do it.
It takes a bit of practice, but once you understand how it works, it's quite easy. Soldering SMD devices with solder paste is easy because the part self-aligns itself on the pads once the solder melts. There are plenty of videos on YouTube showing various ways to use a hot air SMT desoldering station. Instead of declaring defeat and surrendering before you start, watch a few and decide if you can handle it.
-- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
Haha, I actually saw a small pile of those on the shelf at the local (well, only) brick and mortar components retailer in the Boston area, on sale for $8 each in kit form.
I think I'll pick one up next time I don't think I've ever owned a capacitor substitution box before, or really needed one (it's easy to substitute capacitors in Spice) but might come in handy someday, and I mostly trust my own soldering. Maybe I'll splurge on some better quality through-hole caps for it than those ceramic disk....things
** You are thinking of " 40/ 60 " solder that is used by plumbers. 60/40 is ( or was) standard electronics solder.
** Hate the stuff !!!!
To rework a PCB you HAVE to clean ALL of it off before applying 60/460 or 63/37.
.... Phil
I have been building kits and repairing electronics for about 50 years and stayed away from the SMD up to about 3 years ago when I was about
That microscope was the best piece of shop equipment that I have bought in many years. I seem to use it all the time now.
The standard is for the tin content to be first and then the lead.
The 60/40 is most common for electronic solder, but 63/37 is slightly better.
The plumbing is often 50/50, or was before the RoHS and lead free stuff started.
I do agree the solders other than the tin/lead is very bad and hard to work with. As I just do it for a hobby and in the US, anything I do is with the tin/lead. If the area of a board I am working on has the RoHS type solder on it, I remove it from the part I am working on.
It is going to be interisting to see if the devices have the 'tin whisker' problem that high tin no lead content solder can have in a few years.
Sometimes it helps to put some tin/lead solder on the parts you are trying to remove and then get rid of all the old RoHS type solder.
I also have their resistance box, which is very good!
I tossed the cap box.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
I have terrible eyesight, so I got a used Mantis microscope thing.
I steady my hand on a table or something when I solder, especially super fine pitch surface-mount parts. The Metcal iron really, really helps.
You're fine, you're just using cruddy tools.
For really small surface mount stuff, I use a big wedge tip and slop solder on all the pins, shorting everything, then wick it.
A q-tip and acetone cleans things up pretty.
I was afraid of 1206 parts when they first arrived. Now a US8 creates only mild anxiety. 0805's look gigantic.
Desoldering is trickier than soldering surface mount parts. The part is a goner, but you don't want to damage the board. My production people are brilliant, so I let them do the hard ones.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
Not even close. I hold that honor. Long ago I soldered a 25-pin RS232 cable. The blobs were so big I couldn't get the housings on. I didn't think any of the pins were shorted, but I wasn't positive. I brought the cable along when we visited a friend with hardware skills. While we were talking he casually unsoldered my botched job and resoldered it nicely. I probably never soldered again :-(
--
Cheers, Bev
When you stop bitching you start dying.
You bought that NEW? Or was it second/third/fifth hand?
It looks like an idiot tried to modify it. I have trouble imagining a legitimate company letting something that hacked out for sale.
John :-#(#
Denatured alcohol is my go-to PCB cleaning fluid now, acetone is a better solvent but seems to also aggressively maul a lot of different plastics and resins as well.
I absent-mindedly poured a bit in a Styrofoam cup one day, the bottom instantly disintegrates into goop, fun times
John Larkin wrote
Strange, in
It is a good argument (the other pics) to use flexible wires from switches etc to the PCB, not use PCB mounted / soldered user controls. After some switch rotations the solder joints will make bad contact.
New, from Amazon. It arrived that way. I opened it because it didn't work right.
It's Chinese.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
My uncle Sheldon had a TV repair shop and used to babysit me, but he couldn't solder because he always had a beer in one hand and a cigarette in the other. So I sat in his lap and soldered for him, starting about the age of 3.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
Some professional soldering people do that far worse.
The only problem for me in a possible shortcut between the two connections of the rectyfier bridge, an insulation pipe should be welcomed. It surely is the mains rectyfier, so a high voltage that could spike.
You can't see it properly from that angle which I admit looks alarming. If you could view it in 3D, you'd see there's plenty of clearance between those leads and they're very rigid, plus this is the low voltage/high current one and the applied voltage from the mains transformer across that secondary winding is only around 3.3V. I admit it's ugly, but it does the job fine and should last much longer than the failed monolithic bridge it replaces.
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