My laptop which is an pavilion dv1000 keeps powering off when I power it on. What should I do?

Is this something new?

Has there been any changes recently to the machine right before start happening.

Try starting with only AC attached and also only with the battery in the unit to see if same thing happens (just try to maybe narrow down something)

There is also the possibility that the processor fan is not working and overheats quickly and powers off, make sure fans sound like they are working and/or can feel blowing out.