We have received an “No Service” iPhone 7 Plus motherboard from our customer who claimed the motherboard has No SIM error, when we power on and test, we found that there’s a warning sign in the status bar, and therefore confirmed it’s caused by baseband failure. There are a lot of possibilities to create a baseband problem, in our previous article we have shared several baseband repair cases, in the article, we will share more about baseband repair techniques, hope you enjoy our sharing.
Step 1 Troubleshooting
We have received a defective iPhone 7 Plus motherboard from our customer and he claimed the problem is No SIM error. With our troubleshooting, we discover it’s not invalid SIM but baseband problem.
Step 2 Diagnosis
Through our observation, thee baseband power chip has been replaced, and we rule out the baseband power chip failure. The other reasons that can cause the No Baseband are: defective RF chip, defective baseband clock, defective baseband CPU or baseband CPU poor soldering. We will further troubleshoot these components.
Step 3 Repairing
Use the hot air gun to remove the baseband clock, we replace the RF IC as well to save trouble, desolder the soldering pads before install new ones.
Step 4 Final Check
Assemble the motherboard, restore the system and verify the baseband. Enter the system after restoration, baseband recovered, repair completed.
Please refer to below detailed video:
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Tools and Materials Used in This Video:
Hot air gun