The OVP pin is connected to the output voltage ($V_OUT$) via a resistive voltage divider. The internal circuitry compares the voltage at the OVP pin with a reference threshold.
The you are seeing (e.g., backlight flashes then dies). The voltages you've measured on the OVP or VCC pins. If you are looking for a protection bypass for testing. MP3378E - Monolithic Power Systems mp3378e protection pin upd
These pins monitor the current and residual voltage across each LED string. If a channel drops to near-zero volts (LED shorted) or spikes abnormally (LED open), the IC identifies an imbalance and cuts power to protect the panel from uneven thermal dissipation. Step-by-Step Diagnostic and Modification Guide (UPD) The OVP pin is connected to the output
If you encounter a non-functional backlight with UPD suspected, follow this systematic diagnostic flow. The voltages you've measured on the OVP or VCC pins
The MP3378E’s internal gate driver for the boost MOSFET requires a stable VCC (typically 5V) and bootstrap voltage. If the bootstrap capacitor (C_BST) is degraded or the VCC capacitor near the IC has high ESR:
Sets the current for each LED string via an external resistor.
The matrix below highlights the behavior of the key monitoring pins that trigger the MP3378E's safety shutdown sequences: