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 ).
When a dead BDL51 LA-D711P Rev 30 arrives on the repair bench, follow this systematic diagnostic approach using the schematic diagram.
Because an exact Rev 3.0 schematic is rarely available, repair experts recommend the following strategies: Cross-Reference Similar Boards : Use the schematic for the
| Resource Type | Source Location / Link | Notes | | :--- | :--- | :--- | | | DIY-LaptopRepair , BadCaps , Vinafix | Valuable for finding links to resources, troubleshooting specific faults, and requesting BIOS files. | | Photo Reference | DeviceDB | High-resolution motherboard images are critical for identifying component placement when a boardview file is unavailable. | bdl51 lad711p rev 30 schematic work
[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
schematic work is vital for diagnosing dead boards, power rail failures, and charging issues. Architectural Overview of the LA-D711P Motherboard
Since I can't attach files, here are the best ways to find : Measure voltage at the current sensing resistor PRB2
Using a multimeter, check for shorts to ground on all large coils (inductors) near the CPU and RAM. 5. Important Files and Components For repair, you may need the following:
Troubleshooting:
If there is no short on B+ but the board remains unresponsive: Connect the OEM charger or bench power supply. Because an exact Rev 3
Integrated AMD Radeon graphics or an optional dedicated AMD Radeon GPU.
This public link is valid for 7 days and shares a thread, including any personal information you added. This link or copies made by others cannot be deleted. If you share with third parties, their policies apply. Can’t copy the link right now. Try again later.
When troubleshooting a "dead" board using the schematic, technicians focus on the following power sequence:
After replacing the faulty component and verifying the were present, the tech pressed the power button. The fan twitched, then spun. The HP logo appeared on the screen, proving that with the right boardview and patience, even a Rev 3.0 "lost cause" can be brought back to life.