Powerbook PC Problem?

[Spiral Girl]

Hi,

My sister was on her Powerbook PC G4 1.67 GHz 512 MB DDR SDRAM and she went to go check her mail with the default mail app and the whole computer screen went blank and she tried to restart it and the screen only half came on and no internet was showing. After another restart it was all back to normal.

Is it the battery maybe? Is there a way to check the battery in the Mac? Or an app that can scan to see if it's almost dead? This has happened before where it won't restart and after a few retries it goes on but it hasn't happened in a few months.

Any ideas?

S.