Problem: The battery not charging in Dell Inspiron 1525 even with new power adapter and new battery. This is a common problem in Dell Inspiron 1525, usually is a power jack board problem.
1) Test the laptop with a new power adapter, there is two version of power adapter: 65 watt and 90 watt. if the battery charged your original power adapter is defective.
2) Connect your laptop to another battery to see if the problem is the battery or your Laptop, If the new battery works fine, the original battery is defective
3) Usually the battery not charging in Dell Inspiron 1525 a cause the power jack board problem. Disassembly Dell inspiron 1525 and get the power jack board.
Look at the picture below.
Set your Multimeter to buzzer sound and check the continuity between the point number (1) with point number (2).
If you didn’t hear any sound that mean there is a problem in the power jack board, and you need to connect those two points using a wire or any way you choice.
If you heard the buzzer sound while measuring the continuity between point (1) and point (2), this mean there is no problem in power jack board.
4) Check the charger IC chip MAX8731AE and her temperature
5) Check the MOSFET u7, u8 and u5 :
MOSFET u7, u8
Replace the defective chip