Spent 3 hours chasing a capacitor issue that was actually a bad solder joint

I was troubleshooting a power supply board that kept shutting down after 10 minutes, and I swapped out three different capacitors before thinking to check the solder. Turns out a cracked joint on the main filter cap was the real problem the whole time. Anyone else ever waste half a day on something that simple?

3 comments

3 Comments

corablack1mo ago

Three caps swapped before the lightbulb went on, nice. Got to admire the dedication to the wrong problem.

the_ruby1mo ago

Kinda feel like three hours chasing caps is still pretty good if you learned to check the joint first next time. But swapping three caps without looking at the solder first, that's the real time sink right there. At least now you'll never forget to wiggle the leads before swapping parts again.

evan_green521mo ago

Funny you mention wiggling the leads, I remember reading a repair blog years ago about a guy who spent a DAY swapping parts on a dell motherboard. Turned out there was a tiny hairline crack in the trace right under the caps. Wiggling the leads would have found that in two seconds flat. Some of these old cap issues aren't even the cap itself, just the solder joint cracking from heat cycles. I've started just pressing down on components with a plastic spudger while watching the screen, catches 90% of those cold joints. Saved me from exactly this kind of cap-swapping marathon more than once.