Dynabook Toshiba Satellite Pro C50 not charging board repair - when everything goes wrong

Step-by-Step Laptop Charging Issue Repair Tutorial:

1. Identify the Issue:

   • The laptop has a charging issue where it randomly turns on and off when the charger is plugged in and does not charge the battery.
   • The customer also provided spare batteries to be checked.

2. Check the Charging Circuit:

   • Plug in the charger and observe the voltage drop to 10 volts.
   • Note the behavior when pressing the power button and the laptop starts.

3. Identify Potential Faulty Components:

   • Check the high side MOSFET in the charging circuit for any issues.
   • Locate the MOSFETs on the charging board and inspect them for faults.

4. Inspect MOSFETs and Components:

   • Check the MOSFETs for voltage discrepancies between the gate and source.
   • Verify the connections and voltages on the MOSFETs to diagnose any issues.

5. Replace Faulty Components:

   • If the BQ chip is suspected to be faulty, replace it with a new one.
   • Ensure proper placement and functionality of the new chip.

6. Test the Circuit:

   • Plug in the charger and monitor the voltage readings to confirm proper functioning.
   • Check for any abnormal behavior or voltage drops in the circuit.

7. Identify Additional Issues:

   • Investigate further if the laptop is still not powering on or charging properly.
   • Check for any remaining faults or components causing the issue.

8. Replace and Repair Components:

   • Replace any faulty components identified during the testing phase.
   • Ensure all connections are secure and functioning correctly.

9. Test the Charging System:

   • Plug in the battery and charger to verify that the laptop is charging properly.
   • Monitor the charging current and voltage to ensure the battery is charging correctly.

10. Check Spare Batteries:

    • Test any spare batteries provided by the customer to ensure they are functioning correctly.
    • Verify the charging current and voltage for each battery to confirm their condition.

11. Final Testing and Verification:

    • Ensure that the laptop is charging, and all batteries are working as expected.
    • Confirm that the charging system is stable and functioning properly.

12. Conclusion:

    • Summarize the repair process and the steps taken to resolve the charging issue.
    • Provide insights on the troubleshooting process and lessons learned during the repair.

By following these steps, you can effectively diagnose and repair a laptop charging issue, ensuring that the device charges properly and functions as intended.