(typically Pin 1 or similar) must be high (>1.85V) for the chip to function at all. : Disabling protection is
The protection features of the LX1692 are designed to safeguard the IC, the LEDs, and the system as a whole from various potential issues such as overvoltage, undervoltage, overcurrent, and short circuits. These features are vital for ensuring the stable operation of the backlight and preventing damage to the components.
At its core, the LX1692 is a sophisticated PWM controller. It drives the MOSFETs that generate high voltage. However, high voltage comes with high risk. If a transformer arcs, a capacitor shorts, or a lamp disconnects, the results can be catastrophic—not just for the light, but for the PCB traces and the silicon driver itself.
Worn CCFL lamps often cause the protection circuit to shut the system down immediately after ignition.
The ceramic capacitors on the secondary side of the inverter (rated for 1kV to 3kV) often crack. A cracked capacitor creates an arc or a short, which changes the feedback voltage to the protection pin. Fix: Replace all high-voltage ceramic caps.
