Bdl51 Lad711p Rev 30 Schematic Work Updated -
[DC-In: 19.5V] ──> [Isolation MOSFETs] ──> [B+ Rail (PR42)] ──> [3V/5V Regulator (PU2)] │ ┌──────────────────┴──────────────────┐ ▼ ▼ [+5VALW Rail] [+3VALW Rail] │ ▼ [Super I/O (U1)] Step 1: Visual Inspection and Diode Mode Testing
The your laptop is showing (e.g., blinking charging LED, completely dead, spinning fan with black screen).
These handle the main DC-IN rail and are prone to burning out. 3. Repair Tips Without a Schematic bdl51 lad711p rev 30 schematic work
Measure the voltage at the DC jack ( PJDC1 ) to ensure 19.5V enters the board. Check pins 1-3 (Source) and pin 4 (Gate) of PQ24 and PQ25 .
Replace the standby PWM controller or check for shorted caps. Pin 8 of the Main BIOS Chip +3.3 V DC Locate and repair broken copper traces between EC and BIOS. 4. Ohmic Ground Testing Output Inductors (Power Off) More than 10 Ohms A reading of 0 Ohms indicates a dead APU or shorted MOSFET. Advanced Diagnostic Tips for Technicians [DC-In: 19
motherboard is a legendary puzzle found inside many HP 15-ba series laptops. This is a story of a typical "dead" repair session. The Silent Patient
The is a common motherboard found in the HP 15-BA series (such as the 15-ba505ur or 15-BA009DX). If you're facing a "dead" laptop that won't power on, working with this board can be challenging because official schematics and boardviews for Revision 3.0 are notoriously difficult to find. Repair Tips Without a Schematic Measure the voltage
: ACIN signal (tells the system an adapter is connected). 3. Common Fault Components
Before applying power, measure the resistance on all large inductors (coils). A low resistance (near 0 ohms) usually indicates a shorted capacitor or a failed IC on that specific rail (e.g., +1.0VALW, +1.8VALW).
By combining physical inspection, targeted measurements, and a logical map of the circuit derived from the schematic, you can bring any TV hosting the BDL51 LAD711P REV 30 back to life.
Measure voltage at the current sensing resistor PRB2 (downstream of the input MOSFETs). If you do not see 19.5V, check the gates of the input MOSFETs ( PQB1 and PQB2 ).