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What's DOS?
Posts: 1
Registered: ‎07-03-2010
Location: Calif
Message 1 of 1 (370 Views)

Think Pad 390 not charging batteries

My 390 is not charging batteries. I tried several known good batteries.


The power supply in the computer 'sings', I can hear it switching. Computer runs OK.


My power adaptor puts out 16 volts, is that correct?


Lowering the DC input voltage to 14 volts and I do not hear the 'singing".....