Chosen Solution
The top of the screen {like 1/4} is darker then next has lines going through it. The rest is fine.
I am in the process of repairing a Samsung ln40b530p7n with similar issues as you are experiencing. After testing voltages with a multimeter I found the gamma IC on the t-con board has incorrect voltage readings in a few areas. On the board I’m repairing there are 22 test points on the t-con board to check the gamma IC voltages. They are labeled on the t-con board as VGMA1-VGMA22. When checking the voltages they should decrease in voltage in one direction. So for example: VGMA1: 15.23v VGMA2: 14.97v VGMA3: 14.83v VGMA4: 12.61v VGMA5: 11.77v VGMA6: 10.79v VGMA7: 10.06v VGMA8: 9.72v VGMA9: 8.38v VGMA10: 8.23v VGMA11: 7.78v VGMA12: 6.99v VGMA13: 6.79v VGMA14: 6.60v VGMA15: 5.25v VGMA16: 4.82v VGMA17: 4.60v VGMA18: 3.59v VGMA19: 2.65v VGMA20: 0.65v VGMA21: 0.51v VGMA22: 0.29v I found the voltages for VGMA14 @ 7.37v, VGMA15 @ 12.45v, and VGMA16 @ 9.92v. So the increase in voltages there signal a failing gamma ic. The gamma IC is a AS15 F on the t-con board I’m repairing. I believe your t-con board also has an AS15 gamma IC. It seems that these ICs are known to fail. So if you or someone you know can check the voltages in the area I have mentioned with a multimeter than you may be able to determine if the gamma IC is indeed the issue. If so you can find a replacement t-con board or for a harder but far cheaper repair you can just replace the bad IC. I recommend www.shopjimmy.com for TV replacement parts. Hope this is helpful and let me know if you have any questions.
check whether there is a device with a stong magnetic field above the screen, such as a transformer or speaker.
