I have a Toshiba laptop that won’t run on battery, even though it’s a new replacement battery. If you pull the power cord out, it dies instantly. It happens to be a Toshiba Satellite L755-S5110. Any suggestions on how to resolve this problem? Is it worth buying another battery to see if it’s a defective battery? (Unfortunately I don’t have any others around that I could swap out with it.) Is there an easy way to test the battery (say, with a voltmeter) to see if it has a charge? Thanks in advance!