Current sinks for the 4 LED strings; failures here often trigger protection.
Enables the IC and controls brightness via pulse-width modulation. mp3378e protection pin upd
The is a versatile, single-chip integrated circuit designed by Monolithic Power Systems (MPS) for liquid crystal display (LCD) monitor applications. It combines a 4-channel White LED (WLED) controller for backlighting with a high-efficiency buck converter for internal system power. Current sinks for the 4 LED strings; failures
While specific to other ICs like the ACM20005, common technician tricks involve using a diode or resistor to ground a protection pin to see if the backlight stays on. Warning: Bypassing protection on the MP3378E can lead to permanent damage to the IC or the LED panel if the underlying fault (like a short circuit) is not fixed. Pinout Summary (TSSOP-28 EP Package) It combines a 4-channel White LED (WLED) controller