G3 Frontier charger flashes and beeps

[Jimmy_W]

My G3 Frontier system is up to date. When I place it in the Samsung charging dock, it usually beeps constantly and the light in the front flashes back and forth between red and amber. After a few tries, I can get it to charge with a constant red light (until fully charged when it turns green) by holding it firmly in the dock for about 10 seconds. My dock is a Samsung, at least per the label on the bottom. I've had the dock for a year or so, and this problem did not present when it was new. Thanks.