Notebook wont switch to battery power

Hey all I'm hoping maybe somebody will know whats going on here. My girlfriends laptop will not switch over to battery power when she unplugs it from the wall. It also will not boot up when not plugged in. When the computer is booted up while plugged in I checked the battery and it says that it is healthy and only charges to 77%. This leads me to believe that for some reason the computer has decided that it doesn't want to switch from ac/dc power to battery power. is this a mobo issue? is there anything else I can do to diagnose the problem? Thanks in advance.

Edit: The notebook is a Compaq Presario 3000 series from 2 years ago

 

I would check for a BIOS update for her notebook, they fix issues like this.

 

hmm interesting idea. I'll try that when I get home tonight. My guess is that it isn't the battery, would you say that is correct since it does show a charge? I understand the loss of 23% due to the degrading of the battery cells.

 

It could be a power connector issue. The R3000/zv5000 was known for that. My zv5000z thankfully never had that problem, but I know plenty of people who did. Only solution is to send it in to HP for a fix. They are usually very good with warranty service. If her notebook is not under warranty, ask how much it will be to fix. The R3000 is still a good machine.

 

thanks Chaz. I will contact HP tonight after flashing the BIOS.