[TriLUG] hp laptop power problem

[jason tower]

i don't deal with these very often, hoping someone knows more about them 
than i do.  got a hp pavillion dv4 laptop that seems to have a power 
problem.  plugged in w/ battery installed the power led blinks but 
laptop won't boot (comes on a second or two then shuts down again). 
battery removed, no power led at all, and won't power on whatsoever. 
multimeter says power cord is putting out 20v.

bad power brick?  internal power supply problem?  supposedly the battery 
has been replaced with no change.