**iPhone 15 Pro No Network Repair (PP_BASEBAND_PMU Fix)**
A Apple iPhone 15 Pro came in with **“No Service”** and no modem firmware showing in settings—classic baseband fault symptoms.
### Diagnosis
Schematic and boardview tracing led to the **PP_BASEBAND_PMU rail**, which was completely missing (0V). This rail is critical for powering the baseband IC and RF section. Continuity checks revealed an open line, likely caused by a damaged filter component in the PMU output path.
### Repair
* Rebuilt the **PP_BASEBAND_PMU line**
* Replaced the faulty passive component
* Verified no shorts and restored proper voltage
### Result
* Modem firmware reappeared
* Network signal restored
* Stable cellular connectivity
**Conclusion:** A missing **PP_BASEBAND_PMU** line can fully disable network functionality. Restoring this rail brought the baseband back to life.
