Suppose for a moment that you have a Plasma TV that you've bought and owned for a few years now. Let's just say it was a Samsung HPT5054, a fairly popular model back in the day and it had been chugging along just fine for as long as you can remember. As you were preparing for the Dodger game one fine Saturday afternoon with your favorite munchies: Doritos with cheese and guacamole dip, chicken wings marinated in barbecue sauce with a dash of Tabasco sauce (because you're gangsta like that), and grilled cheeseburgers with lettuce, tomatoes, mayo, ketchup, and extra crispy bacon strips (because hey, Los Doyers is playing and you wanted to be sure that you had a good time), you go up to your beautiful Plasma, *click*, and everything seems to be turning on as usual. You hear the Samsung 'twinkle' sound, as your TV slowly begins to power on but wait a minute, you noticed. You hear only the sound of the game just starting to play but there's no picture. No problem, you think to yourself. Maybe the TV is starting to glitch out after so many years of dependable use. It's so old, after all. It was about time that it started having some problems. So you hit the TV (because you remember when you had your gran pappy's old tube TV, hitting it always solved the problem) but still nothing. Ok, you thought to yourself. Maybe it wasn't like those old tube TV's. So then you tried turning it off and turning it back on again but to no avail. Then you tried unplugging it for five minutes before plugging it back in and turning it on again (because you remember your old x86 desktop doing something similar and well, why the hell not?) Nope. That didn't solve it either. You sit there with your munchies and you started to think what could be possibly wrong with it.
This is actually a fairly common problem amongst Plasma TV's. The Y-Sustain Board often times go kaput and you run into the problem of "no picture but still having sound". Everything else seems to work like volume control, changing the channels, and even changing the input from one to next. No problem, you think to yourself. Just replace the Y-Sustain Board and you should be good to go, right? Hold on there, cowboy. Before you go and do that, understand for a moment that Plasma TV's, unlike LCD TV's and LED TV's, is a different type of TV technology and thus, the way it operates is also different. If and when "a part goes out," it works in a domino effect. In other words, when one board goes out, it often times takes out another board with it.
In a Samsung HPT5054, it uses this Y-Sustain and Buffer Board set: LJ92-01490A & LJ92-01491A & LJ92-1492A. Now, inside your TV, the direction of electrical current travels from left to right and when this set is inside your TV, from where you stand with the base of the "TV Stand opening" facing towards you, it would be from the "bottom up" that the electrical current travels. And in this particular TV model, usually the "short" comes from the lower buffer board (LJ92-01492A) that ends up blowing out the Y-Sustain Board. In other words, when the lower buffer board goes bad, it usually takes out the Y-Sustain Board along with it. And before you go jumping the gun and concluding that maybe it's prudent to replace the Y-Sustain Board and just the lower buffer board without also replacing the upper buffer board as well, this is actually not a good idea. Why? Because if the lower buffer board goes bad and takes out the Y-Sustain Board along with it, it is just a matter of time before the upper board goes bad. And then you run into the same problem except this time, it will be the upper buffer board blowing out the Y-Sustain Board. In this case, it's a lot like how your mechanic recommends that when you replace your tires or shocks and/or strut assemblies, that they should be replaced in pairs, rather than individually because of the same rationale: when one goes bad, it's highly probable that the other one is on its way out even though it appears to the naked eye that nothing seems to be wrong with it. And if nothing else, replacing the Y-Sustain Board together with the Buffer Boards will sufficiently eliminate the possibility that the short was coming from the upper buffer board thus minimizing the chances that you would end up blowing out one of the two working boards that you just bought. Ultimately, it saves you time and money to replace them together as a set rather than replacing two of the three only to have one of the old boards blow out on you and taking out one of the two perfectly good board you had just bought a week ago. And these Y-Sustain Boards don't come cheap nor are they easy to find.