Hi all. I recently purchased a broken Samsung UN65KS9800FXZA. The TV would turn on and off with the status light making the appropriate changes. However, the screen was black, no backlights activated, and there was no sound. When the seller sold it to me, he stated that there was sound. He also stated that the problem occurred when he was updating his PlayStation. The screen just went black.
When disconnecting the cable from the LED driver board, the backlights would turn on. With the backlights on, I checked all positive voltages for the LED connectors and they all read fine. I don't believe that the LED's are faulty.
I checked all voltages on the connectors, referencing the service manual and boards, and all were correct with the exception of the TCON board. I ordered a used board from eBay, installed it, and powered the device. The blue indicator on the TCON board flashed a few times and no change on the symptoms. I was never able to get the blue light to activate again. I checked for continuity on the one fuse, on the TCON, and it was ok.
Looking at all of the boards, I do not see any visible damage, discoloration, or burning. There were also no audible sounds when the second TCON failed, just the flashing light.
I went ahead and ordered a new main board and power supply from eBay. After installation, I got sound but still no picture or backlights. The indicator LED on the TCON would still not light up.
After reading some other posts, I learned that a faulty tab bonding board or faulty panel could be the culprit and I'm now hesitant to install another replacement TCON before troubleshooting that board. I pulled off the protective cover, and closely inspected the capacitors and ribbons connecting the board to the panel. They all look the same, and don't show any visible indicators of a short or damage. Additionally, the tabs appear to be properly bonded to the board. Is it possible that a faulty main board or power supply could be the root cause of a failed TCON, or is that type of failure solely caused by components downstream (tab bonding board/panel)?
I can post pictures of whatever would be useful. Also, I have watched the posted video about checking the capacitors on the tab bonding board. I can obtain those readings if necessary. It may take a day or so due to the sheer number of them on the boards.
Thanks in advance! Also, if it would be useful to anyone, send me a message and I can share the repair manual.
When disconnecting the cable from the LED driver board, the backlights would turn on. With the backlights on, I checked all positive voltages for the LED connectors and they all read fine. I don't believe that the LED's are faulty.
I checked all voltages on the connectors, referencing the service manual and boards, and all were correct with the exception of the TCON board. I ordered a used board from eBay, installed it, and powered the device. The blue indicator on the TCON board flashed a few times and no change on the symptoms. I was never able to get the blue light to activate again. I checked for continuity on the one fuse, on the TCON, and it was ok.
Looking at all of the boards, I do not see any visible damage, discoloration, or burning. There were also no audible sounds when the second TCON failed, just the flashing light.
I went ahead and ordered a new main board and power supply from eBay. After installation, I got sound but still no picture or backlights. The indicator LED on the TCON would still not light up.
After reading some other posts, I learned that a faulty tab bonding board or faulty panel could be the culprit and I'm now hesitant to install another replacement TCON before troubleshooting that board. I pulled off the protective cover, and closely inspected the capacitors and ribbons connecting the board to the panel. They all look the same, and don't show any visible indicators of a short or damage. Additionally, the tabs appear to be properly bonded to the board. Is it possible that a faulty main board or power supply could be the root cause of a failed TCON, or is that type of failure solely caused by components downstream (tab bonding board/panel)?
I can post pictures of whatever would be useful. Also, I have watched the posted video about checking the capacitors on the tab bonding board. I can obtain those readings if necessary. It may take a day or so due to the sheer number of them on the boards.
Thanks in advance! Also, if it would be useful to anyone, send me a message and I can share the repair manual.
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