Alright, this is going to be lengthy to a degree, as I'm pretty stumped since I haven't been able to find a solution after sifting through the forums for the last 2 weeks for what's happening. Here's the backstory.,,
Picked this up a couple of weeks ago on CL with a "burn in" band on the top, supposedly from the dad watching a bit too much MSNBC (you'll see it in some of the ghosting). As I was loading it into the car, he threw in a, "Oh, and it liked to turn off about every 2 hours..." After getting it home, I plugged it in and it powered on, although there were quite a few horizontal lines (about 2-4" in length) of black that slowly filled in for the first minute or so as the tv warmed up. After that, I noticed that quite a few pixels were out, but would sometimes light with some colors, or slowly fill in with others (I'll have a video link below).
Deciding to see how long it would run before turning off, I found 2 hours was closer to 20 minutes, at which point it would hang a moment, turn off and immediately back on. If I ran it from there, it would pretty much do the same thing. Only once was I able to get it to do it twice in 5 minutes, which was then followed by the 20 minute cycle.
I have checked all voltages. None were very far off, but I dialed them in anyway (only Vs, Va, and Vsc are adjustable... Ve can be checked). No change. I tweaked the Vs and Vsc about 5vdc each way, but again, with no major changes.
I pulled the SMPS to check caps and transistors and look for cold solder joints. I cleaned up some suspicious joints, and replaced 2 caps that were "underperforming" (they were at the low end of the tolerance spectrum), but again, no difference in the overall performance. All the IGBT's are working well.
I pulled the Y-sus to check caps and IGBT's, and nothing popped out at me, although I'll admit I simply used my Fluke to check capacitance and for shorts on the IGBT's. While that was out, I did a quick y-buffer check and didn't "hear" any shorts.
I pulled the X-main to check all the usual, and found nothing out of the ordinary.
I did the logic board test pattern (I used the proper procedure for the integrated logic/main board on this set), and will post the pics below, as well as a video to show a small section of the screen which may help someone identify what is going on.
Heck, I even brought home a thermal imager from work to see if I could locate any oddly hot spots on the boards, and apart from places I would think should be hot, only the logic/main looked odd (although it may be normal for all I know).
Like I said, since it is "working", I'm having a hell of a time finding the problem. I would rather not spend lots of $$ swapping boards out, as they're not the cheapest for this set, although I'm just about ready to get a Y-sus w/buffer and x-main just t see what happens...
I'll post some pics here, and in the next post, since I don't think they'll all fit.
Picked this up a couple of weeks ago on CL with a "burn in" band on the top, supposedly from the dad watching a bit too much MSNBC (you'll see it in some of the ghosting). As I was loading it into the car, he threw in a, "Oh, and it liked to turn off about every 2 hours..." After getting it home, I plugged it in and it powered on, although there were quite a few horizontal lines (about 2-4" in length) of black that slowly filled in for the first minute or so as the tv warmed up. After that, I noticed that quite a few pixels were out, but would sometimes light with some colors, or slowly fill in with others (I'll have a video link below).
Deciding to see how long it would run before turning off, I found 2 hours was closer to 20 minutes, at which point it would hang a moment, turn off and immediately back on. If I ran it from there, it would pretty much do the same thing. Only once was I able to get it to do it twice in 5 minutes, which was then followed by the 20 minute cycle.
I have checked all voltages. None were very far off, but I dialed them in anyway (only Vs, Va, and Vsc are adjustable... Ve can be checked). No change. I tweaked the Vs and Vsc about 5vdc each way, but again, with no major changes.
I pulled the SMPS to check caps and transistors and look for cold solder joints. I cleaned up some suspicious joints, and replaced 2 caps that were "underperforming" (they were at the low end of the tolerance spectrum), but again, no difference in the overall performance. All the IGBT's are working well.
I pulled the Y-sus to check caps and IGBT's, and nothing popped out at me, although I'll admit I simply used my Fluke to check capacitance and for shorts on the IGBT's. While that was out, I did a quick y-buffer check and didn't "hear" any shorts.
I pulled the X-main to check all the usual, and found nothing out of the ordinary.
I did the logic board test pattern (I used the proper procedure for the integrated logic/main board on this set), and will post the pics below, as well as a video to show a small section of the screen which may help someone identify what is going on.
Heck, I even brought home a thermal imager from work to see if I could locate any oddly hot spots on the boards, and apart from places I would think should be hot, only the logic/main looked odd (although it may be normal for all I know).
Like I said, since it is "working", I'm having a hell of a time finding the problem. I would rather not spend lots of $$ swapping boards out, as they're not the cheapest for this set, although I'm just about ready to get a Y-sus w/buffer and x-main just t see what happens...
I'll post some pics here, and in the next post, since I don't think they'll all fit.
Attached Files
And below is another video of me recording the test patterns from the service menu, which shows another odd phenomenon right out of the gate!
, and should have them by the end of the week!
lol!
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