I have a A505. Power Adapter works fine. When battery is charged it works fine. But eventually the laptop would loose power. I opened the laptop. Found a glue spot on the internal power connector. Apparently dusts get attracted to it and causes a short. Removed the glue between the positive and negative connections. Problem solved.
All you need to do is to obtain two capacitors (10v 1500uf and 16v 1000uf) for a few dollars, and replace them! I have repaired two three receivers so far. The high quality Panasonic capacitors I got from DigiKey: (1) P12356-ND CAP 1500UF 10V ELECT FM RADIAL (1) P12366-ND CAP 1000UF 16V ELECT FM RADIAL