Verify if all power rails are up, including CPU core voltage ( +VCC_CORE ) and graphics power ( +VGA_CORE ).
This is a classic symptom of a power management logic failure. When you plug in the charger, the laptop "turns on by itself, there is no initialization, and it does not turn off with the button".
A laptop schematic is a multi-page diagram representing the motherboard's circuitry. The 10203-1 schematic is broken down into logical sections, each represented on a different page.
A missing secondary power rail, a corrupt BIOS, or a short on a sub-rail like 1.5V_PWR or 1.05V_PCH . 10203-1 la56 mb 48.4jw06.011 schematic
[VIN / DC-IN: +19V] │ ├──► [3V/5V Standby Regulator] ──► +3VALW & +5VALW │ │ │ └──► [Embedded Controller / KBC] │ ▼ (Power Button Pressed) [S3/S0 State Changes] ──► +1.5V_DDR ──► +1.05V_PCH ──► +VCC_CORE (CPU VCore) The Standby/Always-On Stage (ALW)
Both models share the same core hardware platform, and the motherboard is also known under the chassis name.
This motherboard is used in two nearly identical Lenovo models: Verify if all power rails are up, including
A common symptom is the laptop failing to power on or react to the power button. Technicians often check for missing "standby" (dezhurka) voltages or insufficient voltage at the power button (e.g., reports of only 3.7V instead of the expected 3.3V).
Shorted ceramic capacitors (MLCC) on the 19.5V main rail, or a blown entry MOSFET.
| Signal Name | Location on Board (Reference) | Component ID | | :--- | :--- | :--- | | ACDET | Near DC jack | PR301 / PC302 | | +3VLP | Near EC chip | C2001 (positive side) | | SLP_S3# | Under PCH area | R1360 (pull-up) | | PLT_RST# | PCIe slot or WiFi card | Pin 9 on J_WLAN | | +1.05VSUS | Near PCH | PL601 (inductor) | A laptop schematic is a multi-page diagram representing
Desolder the chip and reprogram it with a clean, verified dump using an external programmer like the CH341A or RT809F. Ensure you also flash the EC (Embedded Controller) file if the board uses a dual-chip configuration. Finding Shorted Capacitors Using Injection
Crucial for no-power diagnoses, this page maps how the primary input voltage (19V DC from the charger) steps down into various lower-voltage rails required by individual chips. The System Core Pages