Sn51dp Datasheet -

If a TV display "flashes" and then goes dark, the SN51DP may be detecting a fault in the LED strip and triggering its protection mode. Checking the voltage at Pin 9 (OVP) can help determine if the IC is shutting down the system due to a legitimate over-voltage condition or a faulty sensor.

According to internal block diagrams from older datasheets, the SN51DP uses a bipolar junction transistor (BJT) as the power switch, not a MOSFET. This explains its higher saturation voltage (0.8V typical) compared to modern MOSFET-based converters. sn51dp datasheet

Features an on-chip 3.3V regulator and integrated power and ground planes to simplify circuit design . If a TV display "flashes" and then goes