I'd like to share with you a detailed, step-by-step process we took to solve a common issue faced by many iPhone 8 users. This device was experiencing power issues - it would not turn on, and even when we connected it to a charger, it failed to show any significant power consumption. From our initial diagnosis, we determined the problem likely originated in the motherboard.
Power supply:
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🟪 FoneKong:
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Mechanic power pro max:
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We began the process by methodically disassembling the device, removing screws and carefully separating the chassis from the screen. Once inside, we moved to isolate potential sources of short circuits by disconnecting the battery. With the screen and battery disconnected, we could conduct a more thorough examination.
To investigate further, we connected the device to a lab power supply to measure the motherboard's power consumption. In our lab, we use a variety of tools like the FoneKong 8 in 1 power supply for this purpose. However, even a basic setup for anyone interested in microelectronics should include a tester, microscope, soldering iron, and hot air station.
Our analysis indicated there was indeed power consumption on the motherboard, but it was not reaching the battery connector. However, the test points registered voltages indicating that there was indeed current in the motherboard. This lead us to remove the motherboard for closer inspection. With the help of a thermal camera, we could spot areas of abnormal heat. In our case, intermittent heating was observed in a specific circuit, which suggested a possible short circuit.
🟨 Tester
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We then zeroed in on the circuit showing abnormal heat. Our examination revealed two capacitors in short circuit, indicating a line short. We then removed the U3300 (or "Tigris"), the charge controller IC, which helped us to better locate the short circuit.
For the cleaning process, we applied flux and low-temperature tin paste. The soldering iron tip was used to tin the pads by mixing the old tin with the new one. Using desoldering mesh, we removed all the tin from the surface. The area was then cleaned with contact cleaner or isopropyl alcohol. A short was discovered in the middle of the motherboard.
To fix this, we removed the faulty capacitor and replaced it with a new one. We then soldered it using a precision air station. After soldering, we used a multimeter to verify the component. We confirmed the line short had been resolved with the replacement of the damaged capacitor. Then we resoldered the Tigris at 380ºC and 30% air. With this done, the device successfully powered on using the Mechanic Power Pro Max tool, and power consumption at the lab source showed normal levels for the device.
Through this repair process, I hope to demonstrate the tenacity and dedication needed to successfully troubleshoot and solve such issues. It's crucial to remember that in life, as in micro-soldering, everything is based on trial and error. We must dedicate time, effort, and never stop fighting even in the face of seemingly insurmountable obstacles. In our line of work, every challenge, obstacle, or failure is an opportunity to learn something new. Remember, the road to success might be long and hard, but the results are definitely worth it. Thanks for tuning in, I'm Leonardo, and I'll see you in the next video!
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