Here's the solution for Nokia 6124 classic with charger not supported problem. This solution shows which certain components needs to replace when such kind of problem occurred.
Refer to the solution below and locate the highlighted component on the PCB board. Then do a replacement for that particular component.
Refer to the solution below and locate the highlighted component on the PCB board. Then do a replacement for that particular component.
Nokia 6124C Not Charging solution - charger not supported
The BTEMP (battery temperature) resistor which has a value of 47K is connected to the battery BSI (battery stat indicator) terminal. If the said component become faulty or damaged it will result and show "charger not supported" on the device when the charger is being plug-in. Replacing it will possibly fix the problem.