La-d401p - Schematic

: Designed for the HP Spectre 13-v series, specifically models like the 13-v000nx featuring 7th Gen Intel Core i5 processors.

: Always disconnect the battery before testing power rails to prevent accidental short circuits during probing. DELL Latitude 5490 LA-F401P Schematic - ChinaFix la-d401p schematic

The regulator toggles a MOSFET (internal to U1) at 500 kHz–1 MHz, storing energy in L1. The output voltage is regulated via the R1‑R2 divider. R3 senses the boost‑stage current, feeding back to the internal over‑current protection. : Designed for the HP Spectre 13-v series,

If the laptop turns on and off repeatedly, the issue might lie in the "S0" state rails. The schematic reveals the sequence of Power Good (PG) signals. For example, you can check if the +3VALW rail reaches the EC (IT8226VG) and if the EC replies with RSMRST#. The output voltage is regulated via the R1‑R2 divider

For gaming laptops like the Legion Y520, the GPU (GTX 1050/1060) is a high-failure area. The schematic provides the voltage requirements for the GPU core (VCC_GFXCORE) and memory (VCC_GDDR). If these rails are missing, the schematic helps you trace the controller (e.g., NCP81215) back to its enable pin.