Spent 6 hours troubleshooting a capacitor that wasn't even bad

Had a power supply that kept shutting off after 30 seconds. Checked all the big capacitors with my ESR meter, nothing looked wrong. Replaced them anyway because I was sure that was the issue. Finally traced it to a cold solder joint on the main transformer pin. Fixed it in 2 minutes with a touch of the iron. Has anyone else spent way too long chasing a ghost like that?

2 comments

Log in to join the discussion

Log In

2 Comments

the_robin3mo ago

Bet that cap was fine and you just got lucky with the reflow.

7

samjohnson3mo ago

Man, I used to be the same way. Thought you had to swap every cap in sight just to be sure. But that transformer pin thing got me a few months back on an old Samsung monitor. Sure enough, @the_robin is probably right that the cap was fine and the reflow just fixed the real issue. Now I always check joints first before swapping parts, learned my lesson the hard way.

2