Engr Mobile Phones engr Tunji aka engr Stephoo

19/09/2026

📱 NO SOUND DURING CALLS — BOTH WAYS! 😳🔧

You can call someone, but you can’t hear them… and they can’t hear you either.
You even turn on the loudspeaker, but still — NO SOUND! 🔇

This type of fault can come from the earpiece, microphone, loudspeaker, audio lines, filters, connectors, or even the Audio IC/Codec.

⚠️ The mistake many people make is changing the microphone or speaker immediately without properly diagnosing the audio circuit.

🔧 A good technician follows the audio path and finds the actual cause before replacing components.

If this phone comes to your bench, what would you test FIRST? 👇

19/09/2026

🔧 SOLDERING PASTE vs SOLDERING WIRE — DO YOU KNOW THE DIFFERENCE?

Both are important in phone repair, but they are not used for the same job.

🟦 Soldering paste is commonly used for SMD component rework and hot-air work.

🟧 Soldering wire is commonly used with a soldering iron for connectors, jumper work, tinning pads and general soldering.

Using the right soldering material can make your repair cleaner and easier. 🔥

👨‍🔧 Phone technicians, which one do you use more?

Follow Engr Mobile Phones engr Tunji aka engr Stephoo for more practical phone-repair knowledge. 📱🔧

19/09/2026

18/09/2026

Shout out to my newest followers! Excited to have you onboard! DI Vha Nî, T RA Puu, Steve Ekabe

17/09/2026

Does a crystal oscillator work for phone network? 📡📱

YES — but not directly.

The crystal oscillator provides a precise reference frequency (clock signal) that helps the RF/network circuitry generate and synchronize the frequencies required for cellular communication.

A faulty crystal or its surrounding oscillator circuit can contribute to network problems such as continuous searching, failure to register, or unstable network.

🔧 Phone repair technicians: always identify the crystal’s exact function before replacing it.

Did you know this? 👇
Follow Engr Mobile Phones engr Tunji aka engr Stephoo for more practical phone repair knowledge.

16/09/2026

📱💦 PHONE FELL INTO WATER? DON’T PANIC!

What you do in the first few minutes can make a huge difference. ⚠️

❌ Don’t turn it on
❌ Don’t plug in the charger
❌ Don’t use a hair dryer or direct heat
❌ Don’t put it in rice

✅ Remove it from the water immediately
✅ Power it off
✅ Remove the SIM/SD card
✅ Dry the outside
✅ If possible, disconnect the battery
✅ Clean the motherboard properly with 99% IPA
✅ Allow it to dry completely before testing

⚠️ Important: Water damage can cause corrosion even when the phone appears to work normally. If the phone won’t power on or has issues after water exposure, take it to a professional technician for proper inspection and cleaning.

📌 Save this post — you may need it someday!

Follow Engr Mobile Phones engr Tunji aka engr Stephoo for more practical phone repair tips. 🔧📱

16/09/2026

🔧 MINI BLUETOOTH + AUDIO BOARD — COMPONENT IDENTIFICATION

Can you identify all these components and test points on this board? 👀

From the 5V VBUS, GND, D− & D+ lines to the Audio IC, Bluetooth IC, crystal oscillator, AUX, speaker and battery pads — understanding the board makes troubleshooting much easier.

📌 Save this guide for future repairs.
💬 Which component would you test first if this board is not powering on?

Follow Engr Mobile Phones engr Tunji aka engr Stephoo for more practical phone & electronics repair knowledge.

15/09/2026

🔧 Do you really understand a 20-Pin Screen?

Before replacing or troubleshooting a feature-phone screen, you need to know what each pin does.

VDD, GND, backlight, data lines, control signals — every pin has a job.

Save this guide 📌 and share it with another technician who needs it.

What would you check first: VDD, GND, or the data lines? 👇