Shorted Secondary Rectifier Diodes (Dead / Clicks on and off)
When analyzing the schematic, the board is distinctly divided into two zones separated by a physical isolation barrier (the galvanic isolation gap):
The secondary side of the transformer features high-speed Schottky diodes that rectify the stepped-down AC pulses into smooth DC voltages.
Do not trust random "free PDF download" sites that ask you to install a "download manager." That is malware, not a schematic.
: This is another excellent repository for technical documentation. It hosts a vast collection of service manuals and schematics, which you can find using the direct search link below. 17ips72 schematic work
(like STPS20H100CFP) are used to rectify these voltages for the backlight and audio sections. Troubleshooting & Common Failure Points
The IC receives a small startup voltage from the high-voltage DC line through high-value resistors.
Generates a boosted or regulated voltage to illuminate the display's LED backlights. 2. Deep Dive into the Schematic Sections
The LG 17IPS72 is a standardized power supply unit (PSU) manufactured for LG. It typically handles: Shorted Secondary Rectifier Diodes (Dead / Clicks on
The 17IPS72 is a Switched-Mode Power Supply (SMPS) that integrates several critical stages onto a single PCB:
Lenovo does publicly release schematics, but repair communities share them for board-level repair :
Working on SMPS equipment poses severe risk of electrical shock. Always follow strict safety procedures:
The filtered AC voltage goes directly into a full-wave bridge rectifier diode network. This converts AC into pulsating DC. A large electrolytic bulk capacitor (usually rated for 400V or 450V) filters this pulsation into a smooth DC bus voltage. In regions with 230V mains, this bus sits around 325V DC. PWM Controller and Switching MOSFET It hosts a vast collection of service manuals
To help narrow down your repair, tell me your TV is showing or which component you are currently testing. Share public link
rail. This rail powers the TV's mainboard microcontroller and IR receiver while in standby. Main Output Rails: When the mainboard sends a signal, the main supply activates secondary rails, usually High-current Schottky diodes
: This French-language website also provides technical documentation for the 17IPS72 model.
The driver IC modulates brightness using Pulse Width Modulation based on the BL_ON/OFF and BL_DIM signals sent from the TV's mainboard. 3. High-Failure Components on the 17IPS72