How to check TV LED backlight strips with a multimeter. LG 60LB7100 with intermittent backlight.

We have an LG Television model 60lb7100 that comes on for approximately 10-15 seconds then the picture or backlight goes out and you still have the sound. If we place a flashlight up to the screen we can see an image meaning we have a backlight problem.
If we use a backlight tester to test the strips, then all the strips may light up. However there still may be one leaky led that's causing the TV's backlight to turn off, thus causing a black screen.
This particular troubleshooting method in which we use a multimeter to check the return lines DC voltage can be used on any model television.
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