If I remember correctly the dv7s were made by Compal. What's the OEM model on the motherboard? The Compal ones are usually LA-xxxx where the xxxx are digits. If you search for the OEM model number you might find a schematic. Once you read enough of those you'll understand the power distribution system of laptops in general and have an idea of what to look for.
DC in and the battery B+ is gated via several MOSFETs to the main system power bus. This is at adapter voltage when running on AC, battery voltage when not. It is always live. The battery charger is connected across here. The main bus feeds a bunch of DC-DC converters that generate all the other main rails (5, 3.3, 2.5, 1.8, 1.5, 1.2, 1.05, 0.9, Vcore, etc. --- many laptops will have all of these voltages, each for a specific subsystem; the 1.x are usually things like DDR termination, GPU, ...) When the unit is off these are all turned off. The main bus also supplies a few low power linear regulators (usually only 3.3 and 5v), and these power the embedded/keyboard controller. The EC is what controls the other DC-DC converters and commands them to turn on when you push the power button.
So in your case, check that all the standby rails are OK. If any of them are dead then nothing more will work.