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Shoddy charger


esaj

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Someone's coming tomorrow to test ride the KS16B and maybe buy it off from me, I was going to check that the charger that came with it has the voltage adjusted correctly and if it's off, maybe snap some pictures and do a short write up on how this relatively simple operation's done. 

Plugged it in, nothing, the led doesn't turn on, no voltage on the output. Thought that maybe the power cable's loose, tried tugging it in better, bzzzztt... the charger comes to life, but something's sparking in there, likely the connector is loose.

Opened it up, yanked out the board (it's glued to the bottom of the casing), yup, the other pin of the mains connector was soldered really crappily:

4XxKzaH.png

No biggie, cleaned up what little old solder there is with some flux and solder wick, resoldered, all good. Then I turned around the board and noticed this:

 

YYmlwga.png

Wtf... :facepalm:

The funny thing is, I've actually opened up this charger before to see if I could make heads or tails of the design (turns out, not really :P), and took a picture of it back then too, but I never even noticed before that the second capacitor leg was broken. Probably it has broken off already when they've bent and glued the caps in place.

NSbq92w.jpg

Guess not much QA goes into these either. Now, it does work with just a single capacitor, but seeing that these things are made as cheaply as possible, they don't put those high voltage (relatively) largeish caps there just for fun. I better give the guy one of my other chargers I've used constantly and know to work, and add some 400V caps to my next component order... The loose leg could have shorted the entire thing, as it too had come off from the solder joint on the other side.

 

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  • 3 weeks later...

I replaced the caps for the charger today, and all I can say is that this charger ("Gojusin", apparently the manufacturer) isn't "exactly high quality". Removing the old solder from the (remaining) capacitor legs, I actually lifted of all of the capacitor pads and some of the traces! All of them! I haven't had a pad lift off since I was using some very cheap dot-matrix boards I bought from Aliexpress (and maybe too much heat) years ago. I had to bend the capacitor legs to nearest component legs on the same trace to make sure that a good enough contact is made...

Many of the traces are "topped off" with solder, probably because the copper (assuming it even is copper) layer seems to be really, really thin, maybe to prevent the traces from burning out just by normal operating current. I don't know how it's attached to the substrate, by super glue? :P

Now I kind of wish I hadn't used so "good" caps on this (120uF / 450V long life United Chemi-Con, about 3€ per piece), they'll probably outlast the charger  ;)

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  • 2 weeks later...
On 6/27/2019 at 11:06 AM, esaj said:

Someone's coming tomorrow to test ride the KS16B and maybe buy it off from me, I was going to check that the charger that came with it has the voltage adjusted correctly and if it's off, maybe snap some pictures and do a short write up on how this relatively simple operation's done. 

Plugged it in, nothing, the led doesn't turn on, no voltage on the output. Thought that maybe the power cable's loose, tried tugging it in better, bzzzztt... the charger comes to life, but something's sparking in there, likely the connector is loose.

Opened it up, yanked out the board (it's glued to the bottom of the casing), yup, the other pin of the mains connector was soldered really crappily:

4XxKzaH.png

No biggie, cleaned up what little old solder there is with some flux and solder wick, resoldered, all good. Then I turned around the board and noticed this:

 

YYmlwga.png

Wtf... :facepalm:

The funny thing is, I've actually opened up this charger before to see if I could make heads or tails of the design (turns out, not really :P), and took a picture of it back then too, but I never even noticed before that the second capacitor leg was broken. Probably it has broken off already when they've bent and glued the caps in place.

NSbq92w.jpg

Guess not much QA goes into these either. Now, it does work with just a single capacitor, but seeing that these things are made as cheaply as possible, they don't put those high voltage (relatively) largeish caps there just for fun. I better give the guy one of my other chargers I've used constantly and know to work, and add some 400V caps to my next component order... The loose leg could have shorted the entire thing, as it too had come off from the solder joint on the other side.

 

That's an advanced air gap capacitor

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