1Make sure the charger cord is plugged in and the outlet is getting power.
Step2Look closely at the battery pack. Is there corrosion or leakage? If so, replace the battery immediately.
Step3Test the charger. For DC chargers, set a voltmeter to 25 VDC and touch the contacts with the probes. The meter should read about 1 V more than the charger's rating. If the reading is zero, switch the probes.
Step4Test an AC charger by setting a voltmeter to 25 VAC. Touch the contacts with the probes. The transformer in the charger is bad if you get no reading at all.
Step5Check the contacts. These are metal strips or points located on the appliance and in the charging base. With the charger unplugged, wipe them with a cotton swab. Use a fine emery board to remove visible corrosion.