Boosts the standard DC voltage to the high voltage required by the display's LED string.
Disclaimer: Repairing power supplies involves working with high voltages that can cause serious injury or death. Always follow proper safety procedures, such as discharging capacitors before touching the board and using an isolation transformer if possible. If you are not comfortable working with live AC/DC circuits, please consult a professional.
The differences lie in a few tiny Surface Mount Device (SMD) resistors located on the back of the board, which hook up to the pin of the LED driver IC. If you put a board calibrated for a 43-inch TV into a 49-inch TV, the driver will output insufficient current, resulting in a dim screen or triggering an over-current safety shutdown. Conversely, using a 49-inch board configuration on a smaller screen will over-drive the smaller LED array, instantly burning out the backlights. Always order replacements utilizing the exact barcode production number (e.g., 23XXXXXX) found on the white sticker on the back of the board or TV panel. Common Failures & Diagnostic Steps
: Trace the LED+ and LED- lines to diagnose "no backlight" issues.
Blown fuses and resistors (specifically in the start-up circuit) are common. Replacing these, along with checking for shorted capacitors, often restores function. Resources & Downloads
Vestel 17IPS72 is a common Power Supply Unit (PSU) board found in various LED TV models from brands like Toshiba, Hitachi, JVC, and Finlux. The schematic for this board typically covers the power factor correction (PFC), primary switching, and secondary voltage regulation stages. Technical Overview of the 17IPS72 Schematic Boosts the standard DC voltage to the high
: Using the 17IPS72 schematic from Elektrotanya, check the output voltages to the mainboard (typically 12V and 24V). If these are missing, focus on the primary switching circuit.
This boosts the raw rectified DC voltage up to a stabilized 400V DC across the primary smoothing electrolytic capacitor. The SMPS Step-Down Section
Check the voltage at the backlight connector. If it spikes and then drops, one of your LED strips inside the panel is likely burnt out. If there is no voltage at all, check the driver MOSFET and the boost diode on the board. Safety First! Power supplies contain large capacitors that can hold a lethal charge (400V+) If you are not comfortable working with live
Technicians often encounter specific failure patterns with the 17IPS72 board due to build quality issues, such as weak solder joints and capacitors being pushed to their voltage limits. Vestel 17IPS72 Schematic Diagram | PDF - Scribd
