Pulled a power supply board out of a 2014 Samsung TV in Cleveland and found a blown capacitor I almost missed

Started acting up last Tuesday where the screen would flicker then shut off after 10 minutes. I was about to call it a bad panel until I checked the secondary side of the PSU under bright light. There was this tiny bulge on a 1000uF cap that I almost wrote off as glue residue. Replaced it and the thing fired right back up. Anyone else run into caps that hide their failure like that?

2 comments

2 Comments

sandra_black1mo ago

Yep, ran into that exact thing with a Samsung from 2013. Same deal, tiny bump on a 1000uF cap that looked like glue until I touched it and it crumbled. Samsung loves hiding those bad caps near the heatsinks where they get cooked slow.

markl751mo ago

That 2013 era Samsung stuff was notorious for it. I keep a sharp x-acto knife on my bench just for prying those brittle tops off to check underneath. If it crumbles instead of flexing, you know it's cooked. The fix is usually replacing all the caps in that cluster with low-ESR Panasonic or Nichicon ones, not just the one that popped. I'd order 105c rated caps too, they handle the heat better long term. One tip, put a small fan blowing across the board while you're desoldering, it helps keep the nearby caps from getting more heat damage. Only takes one bad cap to drag the whole rail down and make the PSU act weird.