I've picked up a freebie Samsung pn50a510p3fxza off of craigslist that I'd like to try and resuscitate. It was known to have blown chips on the Y Sustain board. When I pulled the back off of the set, sure enough 2 of the square chips on the Y sustain upper were melted, obviously blown in what looks like a pretty catastrophic event. Original owner described smoke, and I believe him.
Since this was a known issue, I didn't try to power on the set when I first received it (assuming there'd be no picture). I've gotten a replacement remote and upper and lower Y sustain boards off of ebay (ShopJimmy was out of stock). With the y-boards installed, the set starts right up (plays a little jingle sound, and some blue and green random pixels flash during startup). After "boot-up" is complete audio sounds fine (from either an antenna connection or an HDMI Blu-ray player) but the picture is heavily red and white "sparkly" throughout and unwatchable from both sources. I can't even really make out the writing on the menus that come up. There is also a single solid horizontal black line horizontally across the display.
Unfortunately I don't know what things looked like with the old components (although I guess I could put them back in), so don't know if these replacement boards are good. I'm wondering if there was other (hidden) damage done by the catastrophic failure of the sustain/buffer chips.
I left the set to run for a couple of hours. There weren't any power cycling issues, and the picture stayed the same. I tried a "factory reset" sequence using the remote and that had no impact on the image quality either, although it does appear (as best as I can tell) to have reset the TV, prompting for language and other setup criteria when turning on the set.
I've checked Vs and Ve and they're both at spec according to the sticker. I've reseated all the cables I can get to and it hasn't made any difference to the picture. All the glass fuses check out (0 resistance). I don't see any obviously blown caps or other gross problems. I haven't done an exhaustive search for bad solder joints, but again nothing is leaping out at me. There are 2 green LED's that blink in sync on about a one second on, one second off cycle on the central board on the back of the set. There's also a single LED on constantly on a little circuit board that juts out at 90 degrees off the main power supply. I don't see any other visual indicators from the back of the set.
Most of the online stuff I've found centers on power supply issues, but I'm not experiencing startup delays or shut-downs, just the really red picture.
I've got a decent digital multi-meter and an older analog oscilloscope with a 10x probe, and experience with soldering, so I'm willing to dive in and try some component-level investigation and replacement, but I'm not sure where to start. This is a hobby project - we've got other sets in the house that work fine. I don't want to play board replacement roulette at $25-$100+ per pop, when a few dollars in components may do the trick.
I'll try to get some photos uploaded after work today so that you can see the actual picture.
Any suggestions as to what my next steps should be are greatly appreciated.
Since this was a known issue, I didn't try to power on the set when I first received it (assuming there'd be no picture). I've gotten a replacement remote and upper and lower Y sustain boards off of ebay (ShopJimmy was out of stock). With the y-boards installed, the set starts right up (plays a little jingle sound, and some blue and green random pixels flash during startup). After "boot-up" is complete audio sounds fine (from either an antenna connection or an HDMI Blu-ray player) but the picture is heavily red and white "sparkly" throughout and unwatchable from both sources. I can't even really make out the writing on the menus that come up. There is also a single solid horizontal black line horizontally across the display.
Unfortunately I don't know what things looked like with the old components (although I guess I could put them back in), so don't know if these replacement boards are good. I'm wondering if there was other (hidden) damage done by the catastrophic failure of the sustain/buffer chips.
I left the set to run for a couple of hours. There weren't any power cycling issues, and the picture stayed the same. I tried a "factory reset" sequence using the remote and that had no impact on the image quality either, although it does appear (as best as I can tell) to have reset the TV, prompting for language and other setup criteria when turning on the set.
I've checked Vs and Ve and they're both at spec according to the sticker. I've reseated all the cables I can get to and it hasn't made any difference to the picture. All the glass fuses check out (0 resistance). I don't see any obviously blown caps or other gross problems. I haven't done an exhaustive search for bad solder joints, but again nothing is leaping out at me. There are 2 green LED's that blink in sync on about a one second on, one second off cycle on the central board on the back of the set. There's also a single LED on constantly on a little circuit board that juts out at 90 degrees off the main power supply. I don't see any other visual indicators from the back of the set.
Most of the online stuff I've found centers on power supply issues, but I'm not experiencing startup delays or shut-downs, just the really red picture.
I've got a decent digital multi-meter and an older analog oscilloscope with a 10x probe, and experience with soldering, so I'm willing to dive in and try some component-level investigation and replacement, but I'm not sure where to start. This is a hobby project - we've got other sets in the house that work fine. I don't want to play board replacement roulette at $25-$100+ per pop, when a few dollars in components may do the trick.
I'll try to get some photos uploaded after work today so that you can see the actual picture.
Any suggestions as to what my next steps should be are greatly appreciated.
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