That one capacitor that took me 3 hours to find

I was working on an old Sony amp last Tuesday, no power at all. Checked the fuse, good. Traced the main rail, kept finding voltage drops but couldn't figure out where. Turns out it was a tiny ceramic cap that had cracked near the standby transformer, not even the big electrolytic ones I spent an hour testing. Cost me 30 cents to fix but I lost half the day digging around. Has anyone else chased a fault for way too long only to find something stupid simple?

3 comments

3 Comments

the_sam27d ago

Used to roll my eyes at guys who would spend hours poking around a board for a single bad cap. Thought they just didn't know how to use a meter properly. Then I spent four hours on a dead power supply at my desk, checking every resistor and transistor, before I noticed a hairline crack in a tiny disc cap near the rectifier. Couldn't see it until I had a magnifying lamp right up on it. That 30 cent part humbled me real quick.

wendyg4327d ago

Right! I've got a whole drawer of those humbling 30 cent parts. My magnifying lamp has seen more action than my actual meter lately, haha.

nancycooper27d ago

Nah, gotta disagree with the whole "30 cent part humbled me" thing. If you spent four hours chasing a hairline crack in a disc cap, that's on you for not properly testing it first. A meter with a capacitance check or a simple visual inspection under good light should have caught it way sooner. Those magnifying lamps are just crutches for people who skip the basic troubleshooting steps.