NiMH Battery Problem
From VAIO Library
On a lot of older VAIOs, such as the PCG-505, PCG-C1 (A detailed list will be made shortly), there is a green NiMH cell, made up of several identical button cells. This cell corrodes over time, and can destroy the motherboard so please remove it as soon as possible. (Guides will be available for VAIO models affected.)
VAIOs with a corroded NiMH cell do not power up with the battery installed but do power up with the battery removed.