While I had the soldering iron out for the Benq GL2250 monitor power supply repair, I thought I should fix up this pending job.
I had bought some DC-DC converters from eBay in the past. Some were buck converters which meant that the output voltage could higher than the input voltage. Others were standard down converters so will produce a lower voltage. This can be ideal if you want to power 5V devices like a Raspberry Pi from a car battery at 12V.
One of those that I had bought had a three digit meter that could display the input or the output voltage measurement depending on which button was pressed. I had ordered two of them, and when they arrived, I noticed that something wasn’t right about one of them. Sure enough when I opened the sealed packet, the converter came out and a loose capacitor as well. I contacted the vendor, and they were kind enough to come to an arrangement with me.
Anyway, this had been put aside since I only needed to use one of them. But since the soldering iron was out, I thought – why not resolder the capacitor. The capacitor is a surface mount type, and it looked like it had not be flow soldered properly. I used the soldering iron tip to wipe both contacts, so that it flowed the solder on the pads. Then put a drop of flux on each pad, set the capacitor in place – then while holding it down, I touched one pin with the soldering iron tip that was wetted with solder.
Then turn around the board, and do the same with the other pin. Of course making sure that the capacitor was oriented the correct way. After using the 9x magnifier again to visually check it, I decided to wet each pin with the soldering iron again, just to make sure.
Anyway, I was happy with the results and I can put this DC-DC converter away until I need it for some project. Another quick repair – that had been sitting around for a while.
P.S. The black bar or stripe on the capacitor designates the negative electrode.