Venerable M4700 flashing power LED

I have the rugged M4700 that I admit is quite old.  It was my base development system for 5 years.  2 laptops later, I pulled it off my storage shelf and I get the flashing power LED (indicates an improper power adapter).  Yeah, I think not.  These adapters have worked fine for a long long time, but they are as old as the laptop, so maybe they have issues.  I'm looking for practical feedback if you have used 4700s.

The laptop boots fine.  The screen is pristine.  I find it hard to believe that both power bricks have issues, but maybe.  Is there any chance that the flashing LED might be due to a bad battery or power board?

Appreciate any thoughts.