Fix: Hp Probook 4540s Boardview Work
Common board codes for 4540s:
Using the PDF schematic, you suspect the signal (processor hot) is being pulled low. But on the board, where is the resistor that splits PROCHOT# between the CPU and the EC? hp probook 4540s boardview work
Tracing the ADAPTER_EN signal from the Embedded Controller (KBC) is a common fix. If the EC chip isn't powered, search for the 3.3V KBC power source in the boardview. Common board codes for 4540s: Using the PDF