
Wire
Voltage(Vdc)
Red+2.5to+3.2
Black
Ground
•Ifthevoltageiscorrect,replacethesystemboard.
•Ifthevoltageisnotcorrect,replacethebackupbattery.
•Ifthebackupbatterydischargesquicklyafterreplacement,replacethesystemboard.
36ThinkPadT420andT420iHardwareMaintenanceManual