I’ve been having some late-night fun with a rather cheap capacitor tester, along with a collection of capacitors I’ve accumulated from various repairs. It’s supposed to measure capacitance and ESR, which could be quite useful when you’re trying to work out whether an old capacitor has seen better days.

The tester has connections for both ordinary and surface-mounted capacitors, and I’m powering it using one of my little adjustable DC-DC converters. That was originally intended for my Sega Saturn power supply experiments, so at least it’s getting some use!

First up are a few old Xbox capacitors. One gives a reasonably believable result, but the next 3300 uF capacitor produces a reading of around 4800 uF. Hmm, that’s not quite what it says on the tin! Another produces an even stranger result, and I’m beginning to wonder whether this little tester was such a wonderful investment after all.

I also decided to try some capacitors from my Sega Saturn Sophia development hardware. Those horrible pale-green things are certainly distinctive, and a 220 uF capacitor came back with a capacitance reading of just under 240 uF. Not too far off, although the ESR reading was another story. Ohm-tastic!

Interestingly, the tester does seem to notice when something is badly wrong. One of the old capacitors has its base pushing out, and the readings are rather interesting compared with a healthier example. At least it’s useful for spotting some obvious troublemakers.

I’ve got quite a collection of these older components, including a few from the era when bad capacitors were practically everywhere. It would be nice to have something that gives me a reasonable idea of their condition before I start soldering them into anything.

For now, though, I’m not entirely convinced by the accuracy of this little gadget. Some readings look sensible, others are all over the place. What a waste of money! Or perhaps I’ve just found another thing to tinker with.

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