Hello,
I have a Samsung PN58B550 plasma TV. It was given to me, so I opened it up to repair it. I've repaired dozens of LCD TVs before, this one has been quite different though, and I'm almost out of ideas.
When I got the TV, it powered on and displayed a picture, however the picture was dim and everything had a red tint to it. Other than that, the image was uniform, no lines or anything. I inspected every board and found no blown fuses, shorts, or incorrect voltages. After some research, I decided to replace the X-sus board.
After receiving the replacement board, I plugged it in and powered on. The picture was nice and bright again, but the picture quality got worse. The top right section of the display looked perfect, colors were correct and it was bright. The rest of the screen looked crazy, with a lot of incorrect colors and snow. After the TV ran like that for a couple minutes, it powered itself off. Trying to power it on after that, I just get the red light on the front to blink 5 times. I can still here the audible chime when the TV turns on. The power supply clicks 5-6 times.
Looking some more, I found 2 fuses on the y-sus board were blown and one of the IGBT's was shorted.
At this point, I ordered a y-sus board and installed it. I reinstalled the old x-sustain board just in case the replacement was causing problems. Powering on provided the same results, blowing both fuses on that board and shorting out the same IGBT. So I ordered yet another y-sus in addition to new y-buffer boards (both upper and lower). Installing all three of these boards, no fuses are being blown anymore, however I am still getting no display and the same 5 flashes on the front LED!
Researching online, it appears 5 flashes of the power light indicates a power supply problem (correct me if I'm wrong). I disconnected the sustain boards from the power supply, powered on and checked the voltages. All of the voltages match the printing on the power supply (and the service manual) perfectly. I can't see anything wrong with the power supply. A relay clicks 3 times when powering on, I have no idea if that is normal or not.
I decided to go for it and ordered a replacement power supply, installed it today. I'm getting the same results: no display, 5 flashes on the front LED, and the power supply clicks 3 times. Replacing the power supply made no difference at all.
At this point, I've replaced almost every board in this thing. The only boards left would be the main board (where all the inputs are), the logic control board (all the ribbon cables run into this board), the x-buffer board (it's a very simple board, can't see anything that could cause a problem), and a couple boards at the bottom (F-boards? Look pretty simple as well).
After doing a lot of reading on here, I have a feeling there could be a problem with the logic control board. I do get one flashing light on the control board while the TV is powered on. The LED is labeled LED2000, but I have no idea if it's supposed to be flashing or not.
Any help or insight on where to go from here would be greatly appreciated. I've already spent dozens of hours and hundreds of dollars on this repair, anything helps. Thanks!!
I have a Samsung PN58B550 plasma TV. It was given to me, so I opened it up to repair it. I've repaired dozens of LCD TVs before, this one has been quite different though, and I'm almost out of ideas.
When I got the TV, it powered on and displayed a picture, however the picture was dim and everything had a red tint to it. Other than that, the image was uniform, no lines or anything. I inspected every board and found no blown fuses, shorts, or incorrect voltages. After some research, I decided to replace the X-sus board.
After receiving the replacement board, I plugged it in and powered on. The picture was nice and bright again, but the picture quality got worse. The top right section of the display looked perfect, colors were correct and it was bright. The rest of the screen looked crazy, with a lot of incorrect colors and snow. After the TV ran like that for a couple minutes, it powered itself off. Trying to power it on after that, I just get the red light on the front to blink 5 times. I can still here the audible chime when the TV turns on. The power supply clicks 5-6 times.
Looking some more, I found 2 fuses on the y-sus board were blown and one of the IGBT's was shorted.
At this point, I ordered a y-sus board and installed it. I reinstalled the old x-sustain board just in case the replacement was causing problems. Powering on provided the same results, blowing both fuses on that board and shorting out the same IGBT. So I ordered yet another y-sus in addition to new y-buffer boards (both upper and lower). Installing all three of these boards, no fuses are being blown anymore, however I am still getting no display and the same 5 flashes on the front LED!
Researching online, it appears 5 flashes of the power light indicates a power supply problem (correct me if I'm wrong). I disconnected the sustain boards from the power supply, powered on and checked the voltages. All of the voltages match the printing on the power supply (and the service manual) perfectly. I can't see anything wrong with the power supply. A relay clicks 3 times when powering on, I have no idea if that is normal or not.
I decided to go for it and ordered a replacement power supply, installed it today. I'm getting the same results: no display, 5 flashes on the front LED, and the power supply clicks 3 times. Replacing the power supply made no difference at all.
At this point, I've replaced almost every board in this thing. The only boards left would be the main board (where all the inputs are), the logic control board (all the ribbon cables run into this board), the x-buffer board (it's a very simple board, can't see anything that could cause a problem), and a couple boards at the bottom (F-boards? Look pretty simple as well).
After doing a lot of reading on here, I have a feeling there could be a problem with the logic control board. I do get one flashing light on the control board while the TV is powered on. The LED is labeled LED2000, but I have no idea if it's supposed to be flashing or not.
Any help or insight on where to go from here would be greatly appreciated. I've already spent dozens of hours and hundreds of dollars on this repair, anything helps. Thanks!!
. LG plasmas are also decent. Not as good as Panasonic, but a lot cheaper and providing good bang for the buck and good build quality. Better than Samsung.
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