Test the filter capacitors on the secondary side. Vestel boards are known for using capacitors pushed to their exact voltage limits, leading to premature bulging and failure.

Converts the transformer output back to low DC voltages.

Uses a dedicated controller and MOSFET to pulse high frequency DC into the transformer.

Use an isolation transformer when measuring live voltages with an oscilloscope on the primary side.

Boosts and regulates the DC rail to roughly 400V.

If the TV turns on and yields sound but shows a blank screen, the LED driver is often at fault. The 17IPS72 schematic includes an LED step-up converter. Test the output voltage at the backlight connector.