Why can't I connect to Wi-Fi with the correct password? A complete breakdown of the reasons.

You've entered your Wi-Fi password for the tenth time, but your smartphone or laptop keeps giving you the "Connection Failed" or "Incorrect Password" error. Sound familiar? According to statistics, 37% of Wi-Fi connection problems They occur not because of an incorrect password, but for other reasons—from router configuration errors to IP address conflicts. In this article, we'll look at all possible scenarios, why the device does not connect to the network despite the correct security key, and we will give step-by-step instructions for Windows, macOS, Android and iOS.

The peculiarity of the problem is that it can manifest itself selectively: for example, iPhone connects without problems, and laptop with Windows 11 - No. Or a router. TP-Link Archer C6 Shares internet with everyone but one device. We've structured our solutions into categories, from basic checks to in-depth network protocol diagnostics. If you're in a hurry, use FAQ at the end of the article, where answers to the most frequently asked questions are collected.

1. Problems with the password itself: hidden characters and case

Even if you are sure that you are entering the password correctly, 9 out of 10 connection errors are related specifically to it. It's not just typos - modern routers support passwords up to 63 characters case-sensitive, spaces, and special characters are included. Here's what can go wrong:

• 🔹 Key register: Password WiFi_123 And wifi_123 — These are two different keys. On smartphones, the keyboard can automatically capitalize letters.
• 🔹 Hidden symbols: If the password is copied from a message or file, it may contain invisible spaces or line breaks (\n).
• 🔹 Input languageThe Russian letter "e" and the English "e" are visually indistinguishable, but the router perceives them differently.
• 🔹 Expired password: Someone may have changed the security key in the router settings (for example, after a reset).

How to check:

1. Open your router settings (usually at 192.168.0.1 or 192.168.1.1) and find the section Wireless → Security (or Wireless Network → Security).
2. Make sure the field Password (or PSK) contains the exact password you enter. To be on the safe side, copy it from here and paste it when connecting.
3. If the password has changed in an unknown way, reset it to a new one and try connecting again.

2. Wi-Fi Standards Conflict: 2.4 GHz vs. 5 GHz

Modern routers broadcast simultaneously in two ranges: 2.4 GHz (distant, but overloaded) and 5 GHz (fast, but with a smaller coverage area). If your device doesn't support one of the standards or is set to auto-select, connection issues may occur.

Typical symptoms:

• 📱 The device "sees" the network, but does not connect (especially relevant for older smartphones on Android 8 and below).
• 💻 The laptop connects to the network, but the speed is lower than expected (for example, instead of 300 Mbps - 50 Mbps).
• 🖥️ PC with adapter Wi-Fi 4 (802.11n) doesn't see the network 5 GHz at all.

Solutions:

How to divide networks by ranges:

1. Go to your router settings (for example, ASUS RT-AX88U).
2. Find the section Wireless → Professional (or Additionally).
3. Activate the option Enable Smart Connect (or disable it to display networks separately, for example, MyWiFi_2G And MyWiFi_5G).
4. Save the settings and reboot the router.

3. MAC address blocking or device filtering

Many routers (especially corporate ones or those with firmware DD-WRT) support MAC address filteringIf your device isn't connecting, its MAC address may be blocked or not allowed. This feature is often enabled accidentally or configured by the network administrator (for example, in an office).

Signs of MAC blocking:

• 🔒 The device "sees" the network, but after entering the password, it returns an error "Authentication failed".
• 📵 Other devices connect without problems.
• 🔄 After rebooting the router, the connection may be temporarily restored.

How to check and fix:

1. Find out your device's MAC address:
   • On Windows: run the command

     ipconfig /all

     and find the line Physical address for the adapter Wi-Fi.
   • On Android: Settings → About phone → General information → Wi-Fi MAC address.
   • On iOS: Settings → General → About → Wi-Fi Address.

4. DHCP Protocol Failures: Why IP Address Is Not Being Assigned

Protocol DHCP automatically assigns IP addresses to devices on the network. If it doesn't work properly, the device may receive an error like Obtaining an IP address or "Self-assigned IP" (on macOS And iOS). This is one of the most common reasons why a gadget won't connect to Wi-Fi despite the correct password.

Reasons for DHCP failures:

• 🔌 Address pool overload: The router has exhausted all available IP addresses (relevant for networks with 50+ devices).
• ⏱️ The rental period has expired: The device did not have time to renew the IP address after reboot.
• 🛑 IP conflict: Two devices received the same address (rare, but it happens).
• 🔧 DHCP is disabled on the router: Addresses are assigned manually, but your device "doesn't know" this.

How to diagnose and fix:

1. On the device that does not connect, set a static IP manually:
   • On Windows: Control Panel → Network and Sharing Center → Change adapter settings → Wi-Fi Properties → Internet Protocol Version 4 (TCP/IPv4).
   • On Android: In Wi-Fi settings, hold your finger on the network → Change Network → Advanced → IP Settings (Static).

Use an address like this 192.168.1.X (where X is a number from 10 to 254, not occupied by other devices), mask 255.255.255.0, gateway 192.168.1.1 and DNS 8.8.8.8 (Google).

Settings → Local Area Network (LAN) → DHCP Server

DHCP server is enabled

The IP address range is not exhausted

Lease Time: not less than 24 hours

There are no static bindings for your MAC (unless configured)-->

5. Outdated router firmware or adapter drivers

If the router or network adapter of the device is running on outdated software, problems may occur compatibility issues with modern safety standards (for example, WPA3) or protocols (802.11ax). This is especially true for:

• 🖥️ Old laptops with adapters Broadcom or Realtek (produced before 2018).
• 📱 Smartphones on Android 7 and below.
• 📺 Smart TV Samsung or LG 2015–2017.
• 🎮 Game consoles PS4 (models before 2019).

How to update your router firmware:

1. Find out the router model (written on the sticker at the bottom).
2. Download the latest firmware from the manufacturer's official website (for example, for TP-Link Archer C7 - With tp-link.com).
3. Go to the router's web interface and find the section System Tools → Firmware Upgrade (or System Tools → Software Update).
4. Download the firmware file and wait for the process to complete (do not turn off the power!).

How to update your Wi-Fi adapter driver on a PC:

1. Open device Manager (Win + X → Device Manager).
2. Find the section Network adapters, select your Wi-Fi adapter (for example, Qualcomm Atheros QCA9377).
3. Right click → Update driver → Automatic search.
4. If the automatic search does not help, download the driver from the manufacturer's website (for example, for Intel - With downloadcenter.intel.com).

6. External interference and Wi-Fi channel congestion

If your device connects to Wi-Fi, but the connection keeps dropping or fails to establish at all, the problem may be congested airwavesIn apartment buildings there are channels 2.4 GHz often intersect, which leads to interference. 5 GHz The problem is less common, but also possible (for example, due to microwaves or wireless speakers).

Signs of interference:

• 📶 The signal appears and disappears (even near the router).
• 🐢 Speed ​​drops in the evening (when neighbors are actively using Wi-Fi).
• 🔄 The device connects only after multiple attempts.

How to diagnose and fix:

1. Install a Wi-Fi analysis app on your smartphone (for example, WiFi Analyzer For Android or NetSpot For iOS).
2. See which channels are the busiest. In the range 2.4 GHz choose channels 1, 6 or 11 (they do not intersect). 5 GHz - any free channel with numbers 36–48 or 149–165.
3. Change the channel in your router settings:

   Wireless → Channel (or "Channel")

   Save the settings and reboot the router.

4. If the interference is strong, try reducing the transmission power (option Transmit Power or Transmitter power) up to 75–50%. This will reduce speed but increase stability.

7. Reset network settings on the device

If all the previous methods did not help, the problem may lie in local device settings. Operating systems (especially Windows 10/11 And Android) sometimes save incorrect network settings that conflict with the router. Resetting the network settings will return them to factory defaults.

Instructions for different devices:

Important: Resetting network settings on Windows also deletes all VPN profiles and proxy settings. If you're using a corporate VPN, save your connection details beforehand.

8. Hardware faults: router or Wi-Fi adapter

If none of the above methods worked, the problem may be physical malfunction equipment. This is the worst-case scenario, but it also needs to be checked.

Signs of hardware problems:

• 🔌 Router:
  • The Wi-Fi indicator is not lit or is flashing red.
  • The network disappears after 5-10 minutes of work.
  • The router gets very hot (especially the chip) Qualcomm Atheros in models ASUS And Netgear).
• 🖥️ Wi-Fi adapter:
  • The device does not see any network (even public ones).
  • IN Device Manager The adapter is marked with an exclamation mark.
  • After connecting to USB (for external adapters), the network does not appear.

Diagnostics and solutions:

1. For router:
   • Try connecting it to a different power source (not via a UPS).
   • Reset to factory settings (Reset button for 10 seconds).
   • If your router is older than 5 years, consider replacing it (modern models, for example, TP-Link Archer AX6000, support Wi-Fi 6 and less susceptible to overheating).