Laptops should still show some signs of life, even if a CMOS battery has died.... I would expect.
It's possible - but typically, on laptops, the CMOS battery is not a standard CR2032 that are typically found in desktops (and are user serviceable).
They can even be soldered to the board, making a replacement difficult (although not impossible).
Actually:
http
/www.irisvista.com/tech/laptops/Toshiba-Satellite-L505-L505D/remove-laptop-motherboard-1.htm
Given that's a near 10 year old laptop with a Dual Core Athlon, it's probably not economically viable to repair it.