It seems, at a quick glance, you have a blown up component, on the charger.
The underside (surface mount side, second picture), (just below, and a bit to the right of R10) near the bottom middle, a small SOT23 transistor, seems to have blown its lid off (I could easily be wrong, pictures can lead to confusion).
EDIT: Removed section, as I've decided I'm not sure, if I have damaged/broken a charger(s), with over-discharged batteries, or not. Probably NOT, I think it broke, through natural causes.