Vestel 17ips12 — Schematic

For a technician or a hobbyist, the Vestel 17IPS12 is more than just a circuit board; it is the silent heartbeat of an LCD television, tasked with the complex job of converting wall power into the steady voltages needed to bring images to life. The Story of a Power Supply

Imagine a quiet evening interrupted by a television that suddenly refuses to turn on. Behind the plastic casing, the Vestel 17IPS12

power supply unit (PSU) has likely encountered a "villain" in the form of a voltage spike or a worn-out component. To save the device, a technician must consult its "map"—the Vestel 17IPS12 Schematic 1. The Gatekeepers: Protection and Conversion

The journey begins at the AC input. The schematic reveals a series of "gatekeepers"—resistors and capacitors designed to filter noise and protect the delicate circuits downstream. If these fail, the TV remains dark, acting as a fuse to prevent further damage. 2. The Power Regulators Once past the gates, the current meets the STPS20H100CFP diodes

. These components act like traffic controllers, ensuring electricity flows in only one direction to create the +12V and +24V rails required for the TV's mainboard and backlight. 3. The Silent Partners

Scattered across the board are dozens of resistors (ranging from 50 ohms to 100k ohms) and capacitors (from 4n7 to 22u microfarads). These are the silent partners that stabilize the voltage, ensuring that when you press "Power," the screen lights up instantly without a flicker. Technical Snapshot vestel 17ips12 schematic

If you are looking for specific repair details, the 17IPS12 is characterized by: Primary Voltages : Typically produces +12V DC and +24V DC outputs. Key Components

: Uses high-performance diodes and a network of capacitors to maintain power integrity. Design Purpose

: Primarily used in Vestel-manufactured LCD TVs, often rebranded under various budget-friendly labels.

For a complete look at the electrical pathways, you can view the detailed technical diagrams on the Scribd Archive or similar electronics repair databases troubleshooting common failures for this specific board, such as checking the 12V rail? Vestel 17IPS12 Schematic Overview | PDF - Scribd

Overview of the 17IPS12 Board

The 17IPS12 is a single-sided, flyback-based power supply integrating the standby and main power sections. Key specifications: For a technician or a hobbyist, the Vestel

• Input: 100–240V AC, 50/60Hz
• Standby output: 5V (always on, up to 1.5A)
• Main outputs: 12V (primary for audio and panel logic) and 24V (backlight inverter supply)
• Control: Power Management ICs — typically a VIPer22A in the standby section and an LD7535 or OB2269 in the main PWM stage
• Switching MOSFET: Main stage uses an SPP11N60C3 (600V, 11A) or equivalent
• Rectifiers: Schottky diodes (SB5100 for 5V, SB5200 or BYV28-200 for 24V)

The schematic is essential because the board lacks printed component designators in many revisions — only a white silkscreen with numeric IDs (e.g., R815, C910). Without the diagram, tracing voltage rails is nearly impossible.

1. Official Repair Databases

• ElektroTanya.com: A community-driven repository. Search for "Vestel 17IPS12". Look for the PDF version, not a JPEG.
• Manualslib.com: While focused on user manuals, they sometimes hold service manuals that include the 17IPS12 power section.
• Badcaps.net forums: Experienced members frequently attach schematics to repair threads. Search for "17IPS12 schematic" in the forum search.

Typical Breakdown of the Schematic

Once you locate the schematic, understanding its structure is key. The 17IPS12 diagram is usually divided into six logical blocks:

1. EMI Filter & Bridge Rectifier – Comprising L801 (common mode choke), CX801 (X-capacitor), and DB801 (KBP206G or equivalent).
2. Standby Power Supply – VIPer22A in a buck or flyback configuration generating 5V_SB. Its feedback is via PC803 (optocoupler) and TL431.
3. Main PWM Controller – LD7535 (pinout: Vcc, GND, COMP, CS, RI, GATE). It drives Q801 (primary MOSFET) through a small gate resistor (R821 ~ 22Ω).
4. Transformer – T801 (main), T802 (standby). The secondary side shows dual windings for 12V and 24V.
5. Synchronous or Schottky Rectification – D850, D851 for 24V; D830 for 12V. The schematic will show RC snubbers across them (e.g., R848/C850).
6. Protection Circuits – Overvoltage protection via ZD802 on Vcc rail; overcurrent sensing via R832 (0.33Ω) between source of Q801 and ground.

3. PCB Layout Modification (The "Hack")

To integrate this feature without a custom PCB re-spin, we will use the "Jump-Mod" technique on the 17IPS12.

• Location: Locate the resistor connecting the "DIM" header pin to the LED Driver IC (typically labeled R501 or similar near the connector).
• Action:
  1. Remove R501 to isolate the Mainboard connector from the Driver IC.
  2. Solder the "Add-On Module" PWM output directly to the Driver IC side of the R501 pad.
  3. Power the module from the 3.3V Standby rail (Pin 1 of CN1 usually provides this).

📄 Where to Find the Actual Schematic Diagram

I cannot directly post a full schematic image here, but you can find free PDF schematics from these sources:

1. ElektroTanya – Search "Vestel 17IPS12 schematic"
2. ManualsLib / ManualsPlanet – Often have service manuals with 17IPS12
3. Badcaps.net forum – Users frequently upload Vestel PSU schematics
4. YouTube – Search "17IPS12 schematic" – some repair channels show the diagram on screen

🔎 Search string example: "17IPS12 circuit diagram" filetype:pdf Overview of the 17IPS12 Board The 17IPS12 is

Where to Find the 17IPS12 Schematic

Vestel does not publicly release schematics, but they circulate among service centers and online repair communities. Reliable sources:

1. ElektroTanya – Search for “Vestel 17IPS12”. Often includes annotated PDFs.
2. Badcaps.net forums – Users upload schematics and voltage maps.
3. Service manuals for specific TV models – For example, Toshiba 19DV503B or Hitachi 19HBC03 contain the 17IPS12 schematic in appendices.
4. Donor boards – Physically reverse engineering a working board remains the last resort.

⚠️ Beware of scam sites demanding payment for “exclusive schematics.” The 17IPS12 is old enough that genuine PDFs are shared freely in technical forums.

Schematic Design (Add-On Module)

Block Diagram: [Light Sensor] -> [ATtiny13A ADC] -> [PWM Generator] -> [Low-Pass Filter] -> [LED Driver DIM Pin]

Circuit Netlist:

VCC (3.3V Standby) ---- R1 (10k) ----+---- TEPT4400 Collector
                                     |
                                     +---- ATtiny13A Pin 2 (ADC3)
                                     |
GND ---------------------------------+---- TEPT4400 Emitter
ATtiny13A Pin 5 (OC0B/PWM) ---------- R2 (1k) ----+---- CN1 DIM Pin
                                                 |
                                                 +---- C1 (10uF) ---- GND

Logic Flow:

1. The ATtiny reads the voltage from the TEPT4400 ambient light sensor.
2. It maps this voltage to a duty cycle (e.g., Dark Room = 20% brightness, Bright Room = 100% brightness).
3. It outputs a PWM signal, which is smoothed by the RC filter (R2/C1) into a DC voltage (0V - 3.3V).
4. The 17IPS12 LED driver IC sees this DC voltage on the DIM pin and adjusts the output current accordingly.

3. Measuring Correct Voltages

You can measure critical test points: PFC output (should be ~380V DC), 5VSB, and VCC for the PWM ICs. The schematic lists expected voltages.