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c/electronics-repairersumamartinumamartin6h agoTop Commenter

That 'simple' capacitor swap that turned into a 3 day nightmare

I picked up a 2012 Samsung plasma TV last week, dead power supply, figured it was just a few bad caps on the primary side. Popped the board out, saw three bulging caps, replaced them all in 20 minutes flat. Plugged it in and it blew the main fuse instantly, so I spent the next 2 hours chasing down a shorted MOSFET that I missed because it was hidden under a heatsink. Then after I got that fixed, the standby voltage was still off by a whole volt, turned out a resistor had drifted way out of spec from heat stress. Two more days of swapping parts and checking datasheets before I found a tiny crack in the solder joint on the main transformer. The whole job I thought would take an afternoon took me 3 full days of after work tinkering. Has anyone else had a simple capacitor job blow up into something way bigger like this?
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drew_park
drew_park5h ago
Yeah the transformer joint thing is a killer, I've learned to reflow every big component on these Samsung plasma boards as a matter of course now. The heat cycles just wreck those joints over time, and they look totally fine until you poke at them with a pick. Glad you stuck with it though, that's the kind of repair that teaches you more than any textbook ever could.
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piper_burns
Wait, wait - you're telling me you actually poke at these joints and they're lying right on top of the board looking totally fine until you touch them? That's genuinely terrifying lol I've had a few Samsung sets come through that were driving me crazy with intermittent issues, and now I'm wondering how many I just got lucky with. Man, these Korea boards are something else entirely, the way they hide their problems is almost impressive.
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