I got this TV used a year ago. It worked perfectly after I replaced an IC in the SMPS. About a month ago, the picture suddenly started exhibiting several different problems. There is noise throughout the picture, in a mostly horizontal pattern. There are vertical streaks above and below anything bright in the picture. When the video fades to black during a scene change, all of the noise and streaks go away. The picture looks just as bad with the TV's internally generated test patterns.
I adjusted the power supply voltages Va, Vsc, Vs, Ve, and Vset according to the values listed on the PDP, while watching the picture. All of the voltages were close to correct before adjustment. While the Va and Vs voltages had a significant impact on the noise, it could not be cleaned up by adjusting them.
The fact that there are both vertical and horizontal issues makes me suspect the logic board. The fact that the noise is effected by adjusting high voltages not present on the logic board suggests something else, or multiple failures. The fact that all of the picture issues occurred simultaneously suggests a single piont of failure. I don't see any noise or unstability in the power supply outputs. I'm stumped. I don't have spare boards laying around to swap out, and don't want to just buy them until I get lucky. any one have any ideas?
hi to all.I have a samsung HPR4262 and suddenly have a lot of tiny horizontal lines running across my screen. It is the same on all inputs. The lines on the right side of the screen have a red tint to them, on the left side the lines are black. I can see the picture but it is pretty much unwatchable. I want to try the y buffer boards first. I am just hoping that it isn't a bad panel. The tv is 5 years old.