I have an HP dv4000 laptop that shuts down randomly when it's plugged in. What's wrong? How do I fix it?

Question

It does NOT shut down randomly when it's just on battery power (just goes to black and shuts down abruptly.. definitely off).
I've had this computer for about 2 years. It was previously shutting down randomly in general, which I thought might be overheating, but I tried vacuuming out the fans and it helped only a tiny bit. It also didn't shut off this often (now it shuts down after about half an hour on a good day- this is when plugged in). What should I do?

Answer 1

http://www.howtofixcomputers.com/bb/ftopic73146-0-asc-90.html
suggests that it could be a bad power jack.

but most of the comments are about a different series.

http://forum.notebookreview.com/showthread.php?t=148934
says the defect is "very common" but does not seem to have a solution.

http://forum.notebookreview.com/showthread.php?s=a851c0d808c51309108f69460a19ca6a&t=116196
posts that a docking station *might* solve the problem.

Answer 2

attempt to take the battery out and the with the workstation plugged in turn it on. If the workstation is going on then your battery is undesirable. yet another threat is that your means adapter has long previous undesirable (nonetheless greater probable its the battery)