I have the same problem, mine started this way Samsung TV permanent vertical lines
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Last week the screen went completely blank with a gray/black screen. I did light test no image, and I do have backlights on that will lit up once I disconnect main board from power board and sounds works with no problem.
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Any suggestions on what to check or replace ? Is my tcon board integrated with my main board ?
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If any one could share some wisdom and knowledge I would really appreciate it.