I agree with what you assume should be the battery charge level.
(Since full charge would be about 4.2 volts.)
The charger hardware is firmware controlled.
But you have updated that to no avail.
And its "normal operation" when the battery is full would seem to confirm the firmware is functioning as it should.
The only thing I can think of, is a hardware failure.
It might be something as simple as a displaced cable in a connector.
But I am assuming you have given the device a good eyeball inspection while changing the battery.
So it may be a for-real, hardware, hardware failure.
The K2I is getting a bit old, but I have a couple (for the KUAL project) that are still working as they should.
But hey, somebody's has to go first.
