LED TV backlight LED voltage drops from 123 Volts to 52 Volts

[robsims]

Hi,

I have a Berklays 32" LED TV. When i power the Tv on there is sound and the LED screen in front works fine too. But there is no LED backlight. The backlight LED's  don't turn on. When i power the TV on and i measure the output voltage on the main board for the LED backlights, i measure  123 Volts. Gradually the 123 volts drops to 52 Volts. I don't have a LED backlight tester. I only have multimeters. How can i fix this backlight problem. Many thanks in advance