If the backlight flashes and goes out, the ILPI-354 VA protection circuit is likely tripping due to a bad lamp or a faulty inverter transformer.
Recent updates to the ILPI-354 VA documentation highlight specific component values that differ from earlier revisions (such as the ILPI-031 or ILPI-022 series). Key sections of the schematic include:
The ILPI-354 VA functions as the primary power delivery system for the monitor. It converts AC mains voltage into the DC voltages required by the logic board and the high-voltage AC needed to drive the Cold Cathode Fluorescent Lamps (CCFL) or LED backlights. 100-240V AC Typical Outputs: +5V (Logic), +12V (Inverter/Audio) Form Factor: Integrated Power + Inverter (LIPS board) 2. Updated Schematic Breakdown ilpi354 va schematic updated
The +5V and +12V rails are regulated via Schottky diodes (e.g., D10 , D11 ). Leakage here is a common cause of "cycling" power lights. 3. Common Failure Points and Troubleshooting
The "Hot Side" of the ILPI-354 VA contains a large filter capacitor that can hold even after the unit is unplugged. Always discharge this capacitor safely before touching the underside of the PCB. 5. Repair Tips for Modern Technicians If the backlight flashes and goes out, the
Most versions utilize the LD7575 or a similar Green-Mode PWM controller. The updated schematic confirms the startup resistor values (typically high-resistance, e.g., 1M惟) which often fail open.
When replacing diodes, ensure you use Ultra-Fast or Schottky types as specified in the updated schematic to prevent overheating. It converts AC mains voltage into the DC
The is a common power supply and inverter board used extensively in LCD monitors, most notably within various Vizio and HP models. Finding an updated schematic is crucial for technicians looking to resolve common power-on failures or "black screen" issues. 1. Overview of the ILPI-354 VA Board