How To Use MULTIMETER To work Any PHONE - Step by Step TEACHING

Introduction

This tutorial will guide you through using a multimeter to diagnose and repair issues with smartphones. Multimeters are essential tools in mobile phone repair, allowing you to measure voltage, current, and check components. By following these steps, you will learn how to effectively use a multimeter to identify faults in a smartphone that won't power on.

Step 1: Prepare Your Multimeter

• Turn on the multimeter.
• Set the multimeter to the appropriate mode for testing (for most initial tests, use the continuity or diode test mode).

Step 2: Test the Battery Connector

• Locate the battery connector of the smartphone.
• Adjust the multimeter to the diode test setting (often marked with a sound icon).
• Connect the positive probe to the battery ground and the negative probe to the battery positive terminal.
• Check the reading:
  • If you see a reading (not zero), current is flowing, indicating the battery connector is functional.
  • If the reading shows zero, this indicates a short circuit, meaning a component may be bridged.

Step 3: Test the Negative Side

• While still on the battery connector, test the negative side of the connector.
• Connect the probes similarly as in Step 2.
• Ensure that you have a reading indicating that the negative side is connected properly.

Step 4: Inspect Capacitors

• Open the phone casing to access the internal components.
• Identify the capacitors around the power input.
• Test each capacitor:
  • Connect the positive probe to the ground and the negative probe to one leg of the capacitor.
  • If there is no reading or a short (showing zero), the capacitor may be faulty.

Step 5: Clean Connections

• Inspect the connections around the screen and other components.
• If any legs are bridged, use a chemical brush to clean the area thoroughly.
• Perform regular servicing to ensure good contact.

Step 6: Test Power Outputs

• With the battery connected, set the multimeter to measure voltage (set to 20V).
• Check the voltage at the power key and other relevant points:
  • A normal reading would indicate that the power IC is functioning. For example, a reading of 3.1 volts is acceptable.
  • If there’s no reading, this could indicate a problem with the contact.

Step 7: Restore Power

• If issues were identified during testing, clean the necessary contacts or replace faulty components as needed.
• Reassemble the phone and attempt to power it on.

Conclusion

In this tutorial, you learned how to use a multimeter to troubleshoot a smartphone that fails to power on. By testing the battery connector, checking capacitors, and verifying power outputs, you can identify and resolve many common issues. For further practice, consider exploring more complex repairs or enhancing your skills with different models. Remember, regular servicing and clean connections can prevent many issues and extend the life of mobile devices.