Small PDF schematic labelled PA 1650 56LC, most likely the circuit diagram of a power adapter given the PA prefix, though the name does not confirm the brand or rating.

PDF schematic for a PA-1650-56LC adapter, a model code in the style of LiteOn's PA-1650 series, generally 65 W class laptop chargers.

PDF schematic labelled PA-1650-56LC, a code in the style used for 65 W class laptop power adapters, so it most likely covers an AC adapter circuit rather than a…

Schematic in a compact 464 KB PDF, named PA-1650-56LC, a code that appears to be a power adapter model number; the file name gives no brand or further details.