Nothing at all. No light, no fan, no noise.$0 – $180
Usually the power supply on a desktop or the charger brick on a laptop, and the diagnosis is free because it takes four minutes with a known-good spare. About one in five turns out to be the wall socket or a failed surge strip, and that one costs you nothing.
Bring it in. Cheap to find out.
Fans spin, screen stays black.$95 – $260
Either the screen, the cable to the screen, or the graphics chip. The first two are worth doing on almost anything. The third is a soldered part on most laptops, which means the whole board, which is where the price stops making sense on a machine over five years old.
Depends which of the three. Free to determine.
Turns on, hangs on the maker's logo forever.$110 – $190
Nearly always a failing drive. Recoverable, usually with the files intact, and it is the single most common job on this bench. If the machine is still on a spinning hard disk, the replacement makes it faster than it was when it was new.
Fix it. Best money on the list.