The situation when the smartphone Samsung Galaxy M21 A problem that refuses to connect to a wireless network can catch you off guard at the most inopportune moment. The device stops responding to password attempts or gets stuck on the "Obtaining IP Address" status indefinitely, making internet use impossible. Users often encounter this after a system update or a new router, and there's no need to panic in such cases.
The main reason is a software failure in the protocol stack or a conflict in power saving settings, which is typical for shells. One UIHardware, including the antenna module, fails much less frequently than software. In this article, we'll take a detailed look at why. Samsung M21 does not see the network or cannot connect to it, and what steps need to be taken to correct the situation.
It's important to understand that ignoring the problem can lead to a complete shutdown of the communication module, so you need to take action consistently. We'll cover both simple reboot methods and advanced settings within the engineering menu. In 80% of cases, the problem is resolved by resetting network settings without losing the user's personal data. Let's start with the initial diagnosis.
Primary diagnostics and hardware testing
Before delving into the depths of settings, it is necessary to rule out trivial physical causes. Sometimes Samsung M21 The router isn't connecting to Wi-Fi because it's lost connection to the ISP or is overheating. Try connecting another device to the same network; if the problem persists, it's not the phone.
Pay attention to the condition of your smartphone's casing. If the device has recently been dropped or exposed to moisture, the antenna cable inside the casing may have become detached. In such cases, Wi-Fi may only work in close proximity to the router, and the signal will be extremely unstable.
⚠️ Caution: If the phone becomes significantly hot in the camera area while attempting to connect, stop troubleshooting immediately. This may indicate a short circuit in the wireless module, and further attempts to connect may damage the motherboard.
It's also worth checking to see if airplane mode was accidentally activated. Sometimes a system glitch blocks the radio modules, and even after disabling airplane mode, Wi-Fi won't turn on. In this case, a full device reboot will help.
Basic software methods for restoring communication
The most effective way to fix temporary glitches in the Android operating system is to restart network services. Samsung Galaxy M21 This is done not just by turning off the slider, but through the quick settings menu.
Press and hold the power button and select "Restart." If this method doesn't help, try a more radical but safer solution: resetting network settings. This will reset Wi-Fi, Bluetooth, and mobile data settings to factory defaults, but won't delete your photos or contacts.
To perform a reset, go to the menu Settings → General settings → ResetHere you need to select "Reset network settings." After confirming, the phone will reboot, and you will need to re-enter your router password.
☑️ Quick reset algorithm
Often, the problem can be resolved by simply "Forget Network." Find your router's name in the list of available routers, click the gear icon next to it, and select "Delete." This will clear the authorization cache, which may have become corrupted.
Setting date, time, and DNS parameters
One of the hidden but common reasons why Samsung M21 If your device doesn't connect to Wi-Fi, the system time is out of sync. Security protocols (WPA2/WPA3) require the device's time to match the time of the authentication server.
Go to Settings → General Settings → Date and TimeMake sure the "Automatically configure" box is checked. If the time is set manually and is off by even a few minutes, the connection may fail or be disconnected immediately after connecting.
The second important aspect is DNS servers. ISPs sometimes block access when using their DNS servers, or they may be slow. You can manually enter trusted addresses from Google or Cloudflare in your Wi-Fi settings.
To do this, in the Wi-Fi menu, click on your network name (the gear icon), select "Advanced" or "IP Settings," and switch from DHCP to "Static." In the DNS 1 field, enter 8.8.8.8, and in DNS 2 - 1.1.1.1.
| Parameter | Default value (DHCP) | Recommended static value | Purpose |
|---|---|---|---|
| IP address | Automatically | 192.168.1.150 (example) | A unique address on the network |
| Gateway | Automatically | 192.168.1.1 | Router address |
| DNS 1 | From the provider | 8.8.8.8 | Primary name server |
| DNS 2 | From the provider | 1.1.1.1 | Backup name server |
IP Addressing and DHCP Issues
If your Samsung M21 phone displays "Obtaining IP address" and then returns an error, it means the router is unable to assign a unique identifier to the device. This occurs when the router's DHCP address pool is exhausted or an address conflict occurs.
In this situation, manually assigning an IP address is the only option. However, it's important to choose an address that isn't already occupied by another device. Routers typically assign addresses in the range of 100 to 200, so it's safe to choose a number at the end, such as 188.
In the static IP settings (mentioned above), make sure the network prefix matches the gateway address. If the router has an address 192.168.0.1, then the phone must also be online 192.168.0.x, and not 1.x.
⚠️ Important: When manually setting an IP address, avoid using address "1" (usually the router itself) and address "255" (the broadcast address). Also, don't use the same IP address that's already in use by your laptop or TV.
Sometimes changing the MAC address in Wi-Fi privacy settings helps. Modern versions of Android use a randomized MAC address for each network, which some older routers detect as a security vulnerability.
The Impact of Energy Saving and Sleep Mode
Model Samsung Galaxy M21 Equipped with a high-capacity battery, the system aggressively optimizes power consumption. The "Adaptive Power Saving" feature can disable Wi-Fi when the screen is off or block background connections.
Check your battery settings. Go to Settings → Device Care → Battery → Battery Usage LimitsMake sure background activity restrictions are not set for Google and Samsung system services.
There's also a hidden setting called "Wi-Fi in sleep mode." To find it, turn on Wi-Fi, go to advanced settings (the three dots in the corner), and find "Wi-Fi power saving mode." Set it to "Always keep on."
- 🔋 Disable the "Power Saving" mode (battery icon) in the notification shade, as it forcibly disables wireless modules.
- 📶 In the "About phone" → "Software information" menu, check if there is a system update available, which may contain patches for the Wi-Fi module.
- 🛌 Make sure that there is no rule set in Do Not Disturb or Sleep mode to disable the internet.
Secret Samsung diagnostics
Dial *#0011# on your phone, select SIM 1, then Menu (three dots) → Wi-Fi → Wi-Fi AP State. Here you can see the actual signal strength and connection status at the driver level.
Factory reset as a last resort
If none of the software methods helped, it's possible that critical registry errors have accumulated in the system. Reset to factory settings (Factory Reset) will delete all data, but is guaranteed to return the software to its “off the shelf” state.
Before doing this, be sure to create a backup using your Samsung or Google account. After the reset, your phone will be as good as new, and if Wi-Fi doesn't work even with a clean system, it's a 100% sign of hardware failure.
To reset, go to Settings → General settings → Reset → Factory data resetThe process will take several minutes. Your phone may reboot several times during the process.
⚠️ Important: After a factory reset, the initial boot may take up to 10 minutes. Don't try to immediately connect the charger or remove the SIM card at this point; allow the system to fully initialize.
Please note that interfaces and menu layouts may vary slightly depending on the Android version (10, 11, 12, 13) and regional firmware. Always check the menu item names against the latest documentation for your model.
FAQ: Frequently Asked Questions
Why does Samsung M21 see the 2.4 GHz network, but not the 5 GHz?
This may be because the Wi-Fi module in your phone doesn't support the 802.11ac (5 GHz) standard, or the channel your router is using is software-restricted in your region. Try changing the channel in your router settings to 36-48.
My phone connects to Wi-Fi, but it says "No internet access." What should I do?
Most likely, the problem is with DNS or the router itself, which isn't distributing internet. Try connecting the ISP cable directly to your computer. If you can connect to the internet, reset the router using the Reset button.
Can a case block the Wi-Fi signal on the M21?
Yes, if the case has a metal plate for magnetic mounting in the car or is made of thick metal. Remove the case and check the signal strength.
Will flashing my phone help if Wi-Fi isn't working?
Reflashing the firmware via Odin can help if the bootloader is corrupted or the system driver files are damaged. However, if the Wi-Fi chip itself is burned out, software methods will be useless.