The solution below shows the corresponding components that needs for check up and replacement if found damaged.
Nokia N78 Charger No response solution
But ensure first that the charging pin connector is perfectly clean and not damaged before trying to check or replace the above showed mounted components.
IF the chip fuse, filter coils, chip diodes and capacitors is okay the problem may possibly lies on the Charging IC (BETTY IC). Try to reflow/rehea and rework before replacing it. A faulty Charging IC may also result to a fake charging, it means that it shows a charging indication on the LCD screen display but the battery does not charge up at all.