Look at the board very closely especially around the battery area. Take great care to look at the tracks / traces. See if you see any damage. (dark green / black etc..).
Get a digital multi-meter and set it to the continuity test mode (where if you touch the two leads it beeps) and check the traces close / close-ish to the battery area.
If any of them are damaged, clean them carefully with a circuit board cleaner spray & brush (toothbrush is good). If there is no continuity you will need to solder a bridge wire to bridge the broken trace.
