17ips72 Schematic Work
Converts the high voltage into lower rails required by the TV mainboard and backlight. Common outputs include: +12V (Main supply for logic and audio). +24V (Often used for backlight driving). +12V_STBY (Standby voltage for the processor). Common Faults & Repair Steps
If the TV has sound but no picture, the LED driver section of the 17IPS72 may have failed components, such as shorted capacitors or a faulty driver IC. Troubleshooting Checklist Visual Inspection: 17ips72 schematic work
The single most frequent reason a technician searches for the is for a "no power" or "no boot" condition. Let’s map the power sequence using the schematic. Converts the high voltage into lower rails required
| Symptom | Likely Cause | Schematic Area to Inspect | |---------|--------------|---------------------------| | Motor does not spin, IC hot | Shorted low-side MOSFET inside 17IPS72 | Check resistance between phase pins and GND – should be >10kΩ | | Motor spins briefly then stops | Overcurrent trigger or missing back-EMF | Verify sense resistor (pin 23) and all three phase connections | | No FG pulse, motor spins at constant wrong speed | Bad VREF pin or missing PWM signal from controller | Scope pin 32 – should see 0V to 3.3V analog or PWM waveform | | Spindle vibrates but doesn’t rotate | Single phase open circuit | Check continuity from each output pin to motor connector | | IC dead short across Vm to GND | Catastrophic MOSFET failure | Desolder IC; check if short disappears from PCB | +12V_STBY (Standby voltage for the processor)
Regulates the input power from the mains to provide a stable +400V DC output for downstream components. It often utilizes a FAN7529 controller chip and a dedicated MOSFET on a heatsink.
Measure +3VALW at C2302 (near the PCH). If 0V, go to Page 4 (Power tree). See +3VALW is made by PU201. Check Pin 7 (VIN) = 19V. Pin 6 (EN0) = 3.3V. If EN0 is missing, trace back to PWR_SRC_DIV through resistors PR213/PR214.
