Wi-Fi and Bluetooth not working on your phone: complete diagnostic and repair instructions

You are trying to connect to the internet or sync your headphones, but Wi-Fi and Bluetooth on my phone refuse to turn on.This situation is familiar to many: module icons are grayed out, clicking them doesn't do anything, and the settings menu displays a blank space or an error message instead of a list of networks. The causes could be software glitches or hardware problems.

In this article we will look at all possible scenarios — from basic actions like rebooting to in-depth diagnostics using the engineering menu. We'll cover this separately. behavioral features of modules on iPhone and Android devices of different brands (Samsung, Xiaomi, Honor, etc.)We'll also tell you when it's time to take your phone to a service center. If your smartphone stopped detecting networks after a fall, an update, or a battery replacement, you'll find a solution here.

1. Basic checks: what to do first

Before you dig deeper, make sure the problem isn't in the details. In 30% of cases Wi-Fi and Bluetooth don't work due to trivial reasons that can be fixed in a minute.

• 🔄 Restart your phone. Hold the power button for 10-15 seconds until the shutdown menu appears. On iPhone 8 and newer Quickly press and release the Volume Up button, then the Volume Down button, then hold the Side button.
• ⚡ Check the airplane modeSometimes it is activated accidentally (for example, through the quick settings panel). Android swipe down from the top edge of the screen, iPhone — from the upper right corner.
• 📶 Make sure the router is workingTry connecting to a different network or check if the Wi-Fi indicator on your router is lit. If other devices connect normally, the problem is with your phone.
• 🔋 Charge the batteryAt a battery level below 5–10%, many smartphones turn off energy-intensive modules (Wi-Fi, Bluetooth, 5G) to save power.

If after these steps the modules still do not turn on, proceed to the next step. Please note: on some models Xiaomi And Realme There's a "Super Power Saving" feature that turns off background processes, including wireless connections. It can be found in Settings → Battery.

2. Software failures: resetting settings and updates

If basic measures don't help, it's most likely the culprit software conflictThis could be:

• 🤖 Crash after OS update (especially relevant for Android 13/14 And iOS 16/17).
• 📱 Conflict with an installed application (VPNs, antiviruses or "optimizers" are often to blame).
• 🗃️ Corruption of system files (for example, after an incorrect shutdown).

Start with reset network settingsThis will delete saved Wi-Fi networks and passwords, but will restore functionality to the modules:

• On Android: Settings → System → Reset → Reset Wi-Fi, mobile network, and Bluetooth settings.
• On iPhone: Settings → General → Transfer or reset → Reset → Reset network settings.

If this doesn't help, check firmware updates:

1. On Android: Settings → System → System Update.
2. On iPhone: Settings → General → Software Update.

The update may contain fixes for your module. Important: Before installation, make sure your phone is charged to at least 50% and your Wi-Fi is connected to a stable network (or use mobile internet).

Make sure you know the passwords for Wi-Fi networks

Save important data (photos, contacts)

Charge your phone to at least 30%

Disable two-factor authentication (if linked to SMS) -->

3. Diagnostics via the engineering menu (for Android)

If standard methods don't work, it's time to look into engineering menu (also known as Service Mode or Test Mode). Here you can check whether the system recognizes wireless modules at the hardware level.

To enter the engineering menu:

1. Open the app Telephone.
2. Enter the combination:

   ##4636##

   On some models Samsung And Huawei may require:

   #0#

3. Select an item Phone information or Wi-Fi information.

In the menu, pay attention to the following options:

If the modules are not displayed in the engineering menu or their status Disabled, this could mean:

• 🛠️ Disconnecting the antenna (often after dropping or disassembling the phone).
• 🔌 Problems with the module power supply (for example, a swollen battery presses on the board).
• 💻 Module firmware failure (solved by reflashing Fastboot or EDL).

adb shell am start -a android.intent.action.MAIN -n com.android.settings/.TestingSettings

4. Hardware malfunctions: when repairs are essential

If software methods do not help, most likely the problem is hardwareHere are the most common reasons:

• 💥 Fall or impactEven if the phone appears to be intact, the antenna cable may have come loose or the board may have cracked.
• 🔋 Swollen batteryIt puts pressure on the motherboard, damaging the module contacts.
• 💧 Moisture ingressCorrosion on the board can interrupt the Wi-Fi/Bluetooth power circuits.
• 🔧 Poor quality repairsFor example, after replacing the screen, they forgot to connect the antenna.

How to diagnose a hardware problem:

1. External examination: Check if the battery is bulging (lift the back cover if it is removable). iPhone A protruding screen may be a sign.
2. Checking after a fall: If the phone has been dropped, inspect the case for cracks, especially near the camera and charging port (the antennas are located there).
3. Test with another deviceTry connecting to your Wi-Fi from another phone. If it sees the network but yours doesn't, the problem is with your device.

If you suspect a hardware problem, Do not try to disassemble the phone yourself. (especially iPhone or Samsung (with adhesive housing). Contact the service center. Average repair cost:

5. iPhone Features: What to Do if Wi-Fi/Bluetooth Isn't Working

On iPhone Problems with wireless modules are often related to iOS updates or hardware limitationsHere's what's typical for Apple devices:

• 🍏 Crash after iOS updateFor example, after the release iOS 17.2 Many users have complained about Wi-Fi dropping out. The solution is to roll back via DFU Mode or waiting for a patch.
• 📡 Problems with the Broadcom chip. IN iPhone 7/8/X The chip responsible for Wi-Fi and Bluetooth often fails. Symptom: The modules stop working after overheating.
• 🔒 Blocking after screen replacementNon-original displays may cause conflicts with antennas (especially on iPhone 11/12/13).

Instructions for iPhone:

1. Reset network settings (as described above).
2. Update via iTunes/Finder:
   1. Connect your iPhone to your computer.
   2. Open iTunes (Windows) or Finder (Mac).
   3. Select the device and click Refresh (Not Restore!).
3. Checking in DFU Mode (if the phone does not respond):

   1. Connect your iPhone to your PC.
   2. Quickly press and release the Volume Up button.
   3. Quickly press and release the Volume Down button.
   4. Press and hold the side button for 10 seconds until the screen turns off.
   5. Without releasing the side button, press and hold the volume down button for 5 seconds.
   6. Release the side button, but continue holding the volume button for another 10 seconds.

   If the screen remains black, but iTunes/Finder detects the device, you are in DFU ModeNow you can restore the firmware.

If after these manipulations Wi-Fi/Bluetooth still does not work, and in Settings → General → About next to Bluetooth or Wi-Fi address there is a dash - this is 100% hardware failureOn . iPhone With this problem, replacement is most often required Tristar chip (responsible for powering the modules) or the entire communication module.

6. Android Problems: Brand Features and Solutions

On AndroidThe diagnostic algorithm for each device depends on the manufacturer. Let's look at the nuances for popular brands:

For Android The following methods are also relevant:

• 🔧 Clearing the partition cache modem:
  1. Turn off your phone.
  2. Clamp Power + Volume Up to enter Recovery Mode.
  3. Select Wipe cache partition.
• 📦 Removing problematic applications. For example, VPN clients or battery saving apps may block modules.
• 🔄 Rollback to factory firmware through Fastboot or ODIN (For Samsung).

If your phone is on MediaTek-processor (for example, Redmi Note or Realme), try resetting the module settings through the engineering menu:

1. Enter ##36446337##.
2. Go to Connectivity → Wi-Fi.
3. Click Reset Wi-Fi.
How to find out the processor of your Android phone?

1. Install the application CPU-Z from Google Play.

2. Open the tab SOC - there will be a processor model (for example, Snapdragon 888 or Mediatek Helio G95).

3. Alternatively, enter "kernel version" in the settings search - the results will include information about the chipset.

7. When to contact a service center: signs of serious breakdowns

If you've tried all the methods and your Wi-Fi and Bluetooth still aren't working, the problem likely requires professional intervention. Here's precise signs, that you can’t do without repairs:

• 🚨 Modules are not detected in the engineering menu (no MAC addresses, status Disabled).
• 🔥 The phone is overheating in the area of ​​the upper part of the body (the antennas are located there).
• 🔌 The problem appeared after a fall, water damage, or battery replacement..
• 📵 Other wireless functions don't work either. (eg NFC or mobile network).

The cost of repairs depends on the model and type of malfunction. For example:

• Replacement Wi-Fi/Bluetooth module on iPhone will cost 5 000–12 000 ₽ (depending on the model).
• On Android (For example, Samsung Galaxy or Xiaomi) — 2 000–6 000 ₽.
• Repairing a board after moisture damage - from 3 000 ₽ (depending on the degree of corrosion).

Before taking your phone to a service center, check:

⚠️ AttentionIf your phone is under warranty, do not open it yourself! This will void the warranty. Contact the brand's official service center (addresses can be found on the manufacturer's website).

Also keep in mind that in some cases, repairs may not be cost-effective. For example, if iPhone 6s or Samsung Galaxy S7 If the communication module fails, replacing it can cost half the price of a new phone. In such cases, it's better to consider buying a new device.

FAQ: Answers to Frequently Asked Questions

My phone sees Wi-Fi networks but won't connect. What should I do?

If networks are showing up but you can't connect, try:

1. Remove the network from saved ones and connect again (enter the password manually).
2. Change IP settings: In the network properties, select Static IP and enter the data manually (or vice versa - turn on DHCP).
3. Disable VPN or proxy in the settings.
4. Check if it is blocking the connection antivirus or firewall.

If nothing helps, reset your network settings (instructions above).

Bluetooth turns on, but it can't find any devices. What's wrong?
The reasons may be as follows:
• The device you are connecting to is not in search mode (for example, headphones are not in pairing mode).
• The phone is in sleep mode. Secrecy (on some Android this interferes with detection).
• Bluetooth profile conflict (for example, if there was a previous pairing with this device, but it failed).
Solution:
1. Remove the device from the paired list and try connecting again.
2. On Android Clear Bluetooth cache: Settings → Apps → Show system apps → Bluetooth → Storage → Clear cache.
3. Check if your device supports the Bluetooth protocol required for connection (e.g. Bluetooth 5.0 for some headphones).
After replacing the screen, the Wi-Fi stopped working. Is this related?

Yes, this is a common problem! When replacing a screen:

• Could have caused damage antenna cable, which runs next to the display.
• On iPhone A non-original screen may block the operation of wireless modules (due to a conflict with the chip) Taptic Engine).
• The technician might have forgotten to connect the antenna back (especially on Samsung Galaxy with a metal body).

Solution: Return to the service center where you had the screen replaced and ask them to check the antenna connection. If the screen is not original (for example, on iPhone), it may be necessary to replace it with the original one or flash it through iTunes to reset errors.

Is it possible to replace the Wi-Fi module yourself?

Theoretically yes, but:

• On iPhone This is extremely difficult due to proprietary connectors and the need for soldering.
• On Android (For example, Xiaomi or Samsung) the module can be replaced, but you will need:
• Special tool (suction cup, pick, tweezers).
• New module (cost - from 500 ₽).
• Experience in disassembling phones (risk of damaging cables or boards).
• After replacement, it may be necessary to flash the module through Fastboot or EDL.

If you don't have any experience, it's best to contact a service center. Mistakes during self-replacement can lead to complete loss of communication (including mobile network).

Wi-Fi works, but Bluetooth doesn't. Is this a separate module?
In most modern smartphones Wi-Fi and Bluetooth are combined into one module (for example, a chip Broadcom BCM4375 V iPhone or Qualcomm WCN3990 V Android). However:
• If Wi-Fi works, but Bluetooth doesn't., the problem may be in:
• Software failure (for example, a conflict with the device profile).
• Damage Bluetooth antennas (it can be separate from Wi-Fi).
• Malfunctions signal amplifier (on the board).
• On some phones (eg. Samsung Galaxy S20+) the antennas are truly separate, and damage to one does not affect the other.
For diagnostics:
1. Check if the Bluetooth module is detected in the engineering menu (instructions above).
2. Try connecting to a different device (for example, a speaker instead of headphones).
3. If the module is not detected, contact the service center - it may need to be replaced.