If the input is from a transformer:
Because "LAC781P" is not a widely recognized standard industrial part number (like a generic 7805 voltage regulator or a 555 timer), it is likely a , a specific house number for a manufacturer (such as a car audio module, industrial controller, or appliance board), or a specific revision code. lac781p schematic top
If you are looking for the full document for repair purposes, it is hosted on several technical archive sites: HP COMPAQ LA-C781P Laptop Motherboard w/CPU & Fan If the input is from a transformer: Because
One of the first rails to appear is the +3VLP (LDO), which powers the Super IO (EC) chip. it is likely a