Ensure your multimeter's black probe is securely grounded to a solid ground plane (like the metallic casing of a USB port or a screw hole) when measuring voltages.
If the fan spins but there is no display, the issue frequently stems from a corrupted BIOS chip or a failed dedicated GPU power rail.
: Technicians often look for the 3.3V/5V regulator (often a TPS51123 chip). The boardview helps find the exact test points to check for VIN (Voltage In) if the laptop is completely dead.
Ensure your multimeter's black probe is securely grounded to a solid ground plane (like the metallic casing of a USB port or a screw hole) when measuring voltages.
If the fan spins but there is no display, the issue frequently stems from a corrupted BIOS chip or a failed dedicated GPU power rail. hp probook 4540s boardview
: Technicians often look for the 3.3V/5V regulator (often a TPS51123 chip). The boardview helps find the exact test points to check for VIN (Voltage In) if the laptop is completely dead. Ensure your multimeter's black probe is securely grounded