D 600 wont start

While on line the laptop froze it wouldnt shut off the only way to turn off was {cntrl ,alt ,delete.} When I tried to restart the units lights come on on the base but no where else then shuts down.  The screen will not even try to boot. Ive tried replacing the battery with another one . The power supply is lit but does not seam to show the battery charging signal. it also will not start from the a/c plug. Is the power supply posible n/g? or is it somthing else . Please all feedback helpful.