How can I repair/replace the charging circuit on my hp pavilion ze4949

My laptop's LED indicator the lets me know that the battery's charging stopped working,and so did the battery. I've bought 2 additional batteries, neither of which will charge on my laptop; I bought another AC adaptor from HP, with no change either. Both new power sources work fine on a friend's similar laptop. I ran power management/diagnostic, and I get a battery icon with a red line through it, so it recognizes the battery, but says I should consider buying a new battery (Obviously that didn't help). After much research I've come to the conclusion that my laptop's charging circuit is shot, and I can't afford to replace either the motherboard or the laptop; Is there a way to repair or replace the charging circuit so that I'm not limited to computing only in places with available AC outlets ?