iPhone “No Service / SOS Only” — When Baseband Fails and How Mainboard Repair Saves It
Baseband failure is the most common reason an iPhone loses signal in New Zealand.
Here’s how to identify it, why it happens, and when mainboard repair is worth doing.
iPhones With Baseband Faults Keep Coming In
Many customers walk into our Christchurch and Auckland shops with the same complaint — their iPhone suddenly shows
“No Service,” “Searching…,” or the IMEI disappears.
Since New Zealand’s 3G shutdown, these issues appear more often.
We handle these mainboard-level jobs daily, especially on models like iPhone 7, X, XR, XS, 11, and 12 series.
If Your Phone Suddenly Lost Signal, You’re Not Alone
Many people assume the problem is with the SIM card or the carrier.
Others think a software update caused it.
These situations feel frustrating because the phone works fine for Wi-Fi, apps, and camera — only mobile signal disappears.
We understand. This is exactly what a Baseband fault looks like.
Real Repairs We See in NZ
- iPhone 7 — No Service after drop (Baseband PMU line cracked)
- iPhone X — Baseband CPU joint failure from board flex
- iPhone 11 — Stuck on “Searching…” after water damage
- iPhone 12 — IMEI missing, Modem Firmware blank
Each case required board-level repair. Some were successful. Some were beyond repair due to board warp or corrosion.
What Baseband Does (And How to Identify Failure)
The Baseband IC is responsible for all mobile communication — voice calls, SMS, and data.
When it stops working, the phone loses cellular function even though everything else feels normal.
Common Symptoms
- “No Service” or “SOS Only” always displayed
- Modem Firmware is blank in Settings → General → About
- IMEI missing or showing as unknown
- Searching… loop even after SIM replacement
- iTunes restore doesn’t fix the issue
Why Baseband Fails
- Board flex from drops (common on iPhone 7, X, 11)
- Corrosion from water or moisture
- Heat damage around the PMU and RF section
- Low-quality previous repair (shield removal, reflow damage)
What Repair Involves
Fixing Baseband faults is a mainboard-level job — reballing, jumper line repair, or IC replacement depending on the failure.
Success rates vary by model and damage severity. Some boards with heavy corrosion or warp cannot be revived.
Does This Affect Wi-Fi or Bluetooth?
No. Baseband has no direct connection to Wi-Fi/Bluetooth — they run on separate chips.
If all three fail, the cause is usually physical damage affecting multiple circuits, not Baseband itself.
Related Guides
Need help with an iPhone Baseband issue?
Christchurch: 03 343 1078 | Auckland Westgate: 09 392 0039
www.ezirepair.co.nz