Had the same problem in the past. Look for several solutions but couldn't find one. Opted for buying a new charger.

http://www.amainhobbies.com/product_...-AC-DC-Charger

I love this charger. It's so easy to use that I ended buying two (2) more. Very accurate and the touch screen makes it almost impossible to make mistakes. I charge my Life 3800 mah batteries with no problem.