Bdl51 Lad711p Rev 30 Schematic Work - __full__

The BDL51 LA-D711P Rev 3.0 is a motherboard primarily used in HP 15-BA, HP 15-AY, and HP 255 G5 laptop series. Because official schematics for this specific revision can be difficult to find, technicians often refer to the highly similar LA-D704P or LA-C801P schematics for cross-reference. 1. Initial Diagnostic Steps

Step-by-Step Tracing:

  1. Start from the AC inlet. Mark the fuse, then follow the copper trace to the bridge rectifier. Note the polarity.
  2. Identify the primary ground (negative of main capacitor) and secondary ground (negative of 12V output). They are isolated.
  3. Find the standby IC (small 7-8 pin chip near a tiny transformer). Note all resistors connected to its VCC and FB (feedback) pins. These are the startup and regulation networks.
  4. Trace the optocoupler (IC801). Its phototransistor side goes to the PWM IC's FB pin. Its LED side goes to the TL431 on the secondary. This is your main voltage regulation loop.
  5. For the LED driver: Locate the large inductor (L701) and the MOSFET next to it. The drain of that MOSFET goes to the inductor. The source goes through current sense resistors to ground. The gate comes from the LAD711P IC.
  • Over Current Protection (OCP) triggered: One LED strip is shorted, causing excessive current.

    , a dual Schottky diode (SOT323 package) located near the charger IC that protects the power supply. Core Voltages bdl51 lad711p rev 30 schematic work

    . For this specific board, a 25B64 8MB IC is typically used, and core voltages should be verified (0.8V for core, 1.2V for graphics) before flashing. Power Circuit Protection : Components like the The BDL51 LA-D711P Rev 3