{"id":2181,"date":"2020-04-07T00:00:00","date_gmt":"2020-04-07T00:00:00","guid":{"rendered":"http:\/\/192.168.2.19:8666\/?p=1"},"modified":"2023-10-24T16:44:57","modified_gmt":"2023-10-24T08:44:57","slug":"troubleshoot-dead-iphone-cpu-repair","status":"publish","type":"post","link":"https:\/\/rewa.tech\/es\/troubleshoot-dead-iphone-cpu-repair\/","title":{"rendered":"Soluci\u00f3n de problemas de un iPhone muerto CPU Reparaci\u00f3n"},"content":{"rendered":"

The CPU of mobile phones functions much like the brain of our body, making it a critical component.<\/p>\n

When it comes to mobile phone repair, addressing CPU issues can be quite complex.<\/span><\/p>\n

In this article, we will explore how to troubleshoot and repair a common problem with the iPhone 7 not turning on, attributed to pseudo soldering of the CPU.<\/p>\n

Problema<\/h2>\n
    \n
  1. \n

    No Response When Turning On the Phone<\/strong><\/h3>\n
      \n
    • Press the power button, but there’s no response.<\/li>\n<\/ul>\n<\/li>\n
    • \n

      Power Supply Test<\/strong><\/h3>\n
        \n
      • Desmonta el tel\u00e9fono.<\/li>\n
      • Connect the phone to the DC Power Supply.<\/li>\n
      • Pulsa el bot\u00f3n de encendido.<\/li>\n
      • The current pointer remains static at 50mA-60mA.<\/li>\n
      • Connect the phone to a computer; the device cannot be recognized, suggesting USB IC or logic board power supply issues.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n

        \u00a0<\/p>\n

        Diagn\u00f3stico<\/h2>\n

        To diagnose and potentially resolve the issue:<\/p>\n

          \n
        1. \n

          Testing Power Supply<\/strong><\/h3>\n
            \n
          • Remove the logic board.<\/li>\n
          • Connect the battery connector to the DC Power Supply.<\/li>\n
          • Test power button functionality.<\/li>\n
          • Measure the 16 rails of the logic board power supply, ensuring the values are within normal ranges.<\/li>\n<\/ul>\n<\/li>\n
          • \n

            Replacing USB IC<\/strong><\/h3>\n
              \n
            • If power supply measurements are normal, replace the USB IC.<\/li>\n
            • Attach the logic board to the PCB holder.<\/li>\n
            • Carefully remove part of the shield plate.<\/li>\n
            • Detach the USB IC using a Hot Air Gun.<\/li>\n
            • Clean the bonding pad.<\/li>\n
            • Solder a new USB IC and test; if the problem persists, proceed to troubleshooting the CPU.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n

              Soluci\u00f3n de problemas<\/h2>\n

              Upon identifying CPU-related issues:<\/p>\n

                \n
              1. \n

                Re-soldering the CPU<\/strong><\/h3>\n
                  \n
                • Remove the shield plate with a Hot Air Gun.<\/li>\n
                • Apply high-temperature tape to protect nearby components.<\/li>\n
                • Carefully detach the CPU from the board using a Hot Air Gun.<\/li>\n
                • Clean the bonding pad and remove the solder from the CPU.<\/li>\n<\/ul>\n<\/li>\n
                • \n

                  Reballing the CPU<\/strong><\/h3>\n
                    \n
                  • Position the BGA Reballing Stencil.<\/li>\n
                  • Apply Solder Paste evenly on the stencil.<\/li>\n
                  • Heat the solder balls evenly with a Hot Air Gun.<\/li>\n
                  • Allow the CPU to cool for 2 minutes.<\/li>\n
                  • Apply BGA Paste Flux to the bonding pad.<\/li>\n
                  • Position the re-balled CPU and solder it with a Hot Air Gun.<\/li>\n
                  • Limpiar con PCB Cleaner.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n

                    Volver a montar y probar<\/h2>\n

                    Now that the CPU-related issue has been addressed:<\/p>\n

                      \n
                    1. \n

                      Montaje<\/strong><\/h3>\n
                        \n
                      • Install the logic board and the display assembly.<\/li>\n
                      • Connect the battery and press the power button.<\/li>\n<\/ul>\n<\/li>\n
                      • \n

                        Pruebas<\/strong><\/h3>\n
                          \n
                        • The phone should turn on normally.<\/li>\n
                        • Run a function test to ensure that all components are functioning correctly.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n

                          Conclusi\u00f3n:<\/h2>\n

                          By following these steps, you can successfully troubleshoot and repair CPU-related issues in mobile phones. In this specific case, the iPhone 7 not turning on due to pseudo soldering of the CPU, our comprehensive process has resolved the problem, allowing the device to function as expected.<\/p>\n

                          Herramientas utilizadas<\/p>\n