How to find or reset the Wi-Fi password on a D-Link DSL-2640U router

Router D-Link DSL-2640U — a popular model that's still used in many homes and offices despite its age. If you've forgotten your Wi-Fi password or bought a used device without connection information, don't panic. There are several ways to restore network access, from simply checking the sticker on the device to a full reset.

In this article we will look at all possible methods, including those that work even if you don't remember your admin panel login/password. Important: Some actions may result in the loss of your current settings, so Prepare the data from your provider in advance (username, connection type, VPI/VCI, etc.).

If your DSL-2640U If your device displays errors when connecting or flashes red, the problem may not be with the password, but with hardware issues. In this case, first check diagnostic section at the end of the article.

1. Password on the router sticker: where to look?

The fastest way is to look at the factory data on the device case. D-Link DSL-2640U the sticker is usually located on bottom panel (less often on the back wall). Look for the following fields:

  • 🔑 SSID (or Network Name) — the name of your Wi-Fi network.
  • 🔐 Password (or Key/Passphrase) — factory password.
  • 🌐 IP address (usually 192.168.1.1) - to enter the control panel.
  • 👤 Username/Password — admin login and password (most often admin/admin).

If the sticker is worn off or missing, try the standard combinations for D-Link:

  • 🔹 Network name: dlink, DSL-2640U or WiFi_XXXX (where XXXX are the last digits of the MAC address).
  • 🔹 Password: 12345678, admin, password or an empty field.
⚠️ Attention: If the sticker is missing and the default passwords don't work, someone has already changed the settings. In this case, proceed to the next steps.
📊 Have you already tried connecting with the factory data from the sticker?
Yes, but it didn't work out
No, I just found out about the sticker.
There is no sticker on my router.
I don't remember whether I tried it or not.

2. Login to the Admin Panel: How to View the Current Wi-Fi Password

If you know the login and password for your router's web interface (or they're the default ones), you can find out the current Wi-Fi password through the settings. To do this:

  1. Connect to the router via cable (recommended) or Wi-Fi (if you remember the old password).
  2. Open your browser and type in the address bar 192.168.1.1 (or another IP from the sticker).
  3. Enter your login and password (default) admin/admin).
  4. Go to the section Wireless → Security (or Wi-Fi → Security Settings in Russian-language firmware).
  5. In the field Pre-Shared Key (or Network key) the current password will be displayed.

If section Wireless If it's missing, your firmware may have a different interface. Try these paths:

  • 🔹 Setup → Wireless Settings
  • 🔹 Advanced → Wi-Fi
  • 🔹 Network → WLAN
⚠️ Attention: In some firmware the password is displayed as asterisks (). To see it, right-click on the field, select "View Code" (or Inspect in the browser) and find the line with in the HTML code type="password". Replace password on text — the password will become visible.

Check the cable connection to the LAN port (not WAN)|

Try a different browser (Chrome, Firefox, Edge)|

Disable VPN/proxy|

Clear your browser cache or use incognito mode|

Try IP addresses 192.168.0.1 or 192.168.10.1

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3. Resetting the router to factory settings: when is it necessary?

If you don’t remember your login details for the admin panel, but the standard combinations (admin/admin) don't work, the only way out is full resetThis will reset the router to factory settings, but All personal settings (including Wi-Fi password, ISP connection type, and PPPoE data) will be lost..

To reset DSL-2640U:

  1. Find the button on the back panel Reset (usually recessed into the body).
  2. Take a paper clip or a toothpick and press and hold the button 10-15 seconds.
  3. The indicators on the front panel should flash and go out - this is a signal of a successful reset.
  4. Wait 1-2 minutes for the router to reboot.

After reset:

  • 🔹 Connect to the network with the factory name (see sticker).
  • 🔹 Log in to your admin panel 192.168.1.1 with login/password admin/admin.
  • 🔹 Set up your internet connection (data from your provider) and change your Wi-Fi password.
⚠️ Attention: If your router doesn't provide internet access after resetting, check your settings. WAN (or Internet). For a PPPoE connection (Rostelecom, Dom.ru), you will need to enter your provider's login and password. For a dynamic IP (Beeline, MTS), MAC address cloning may be necessary.
What to do if the Reset button does not work?

If after holding the button Reset The router won't reset, try:

1. Turn off the power, hold down Reset, turn on the power and hold the button for another 20 seconds.

2. Use another sharp object (needle, thin screwdriver).

3. Check if the button is stuck - sometimes physical cleaning is required.

If nothing helps, the memory chip may be faulty (requires repair).

4. Connecting via WPS: Bypassing the Password Without Resetting

If your router has a button WPS (Wi-Fi Protected Setup), you can connect to the network without entering a password. This method only works if:

  • 🔹 The WPS function is enabled in the settings.
  • 🔹 Your device (phone, laptop) supports WPS.
  • 🔹 The router has not been reset previously (otherwise WPS may be disabled).

Connection instructions:

  1. Click the button WPS on the router (usually it is signed or marked with the 🔄 icon).
  2. On your device (e.g. Android), go to Wi-Fi settings, select the network DSL-2640U and click "Connect via WPS".
  3. Please wait 1-2 minutes and the connection will be established automatically.

After connecting via WPS:

  • 🔹 Go to the admin panel and look at the password (see Section 2).
  • 🔹 Or immediately change the password to a new one in the Wi-Fi settings.
⚠️ Attention: WPS is considered an insecure protocol. After access is restored disable WPS in the router settings (Wireless → WPS) to avoid network hacking.

5. Alternative methods: if nothing helps

If none of the above methods worked, try the following options:

Way When to apply Risks/Limitations
Connection via cable without a password If you only need to set up a router and Wi-Fi is not important Doesn't provide access to the wireless network, only to the admin panel
Using a backup copy of the config If you previously saved your router settings to a file The file may be outdated or corrupted.
Feedback from the provider If the router was provided by a provider (for example, Rostelecom) They may require a contract or passport information.
Flashing firmware via TFTP If the router is bricked and does not respond to reset Difficult for beginners, risk of bricking the device

To connect via cable:

  1. Connect the router and the computer with a patch cord (to any yellow port) LAN).
  2. Open 192.168.1.1 in the browser.
  3. If it asks for a password, try admin/1234/password.

If your router was provided by your ISP, call support and let them know you forgot your Wi-Fi settings. They may have a backup of your settings. To do this, you'll need:

  • 📄 Contract number.
  • 🆔 Owner's passport details.
  • 📞 Router MAC address (on the sticker).

6. Setting up a new password: how to make it secure?

After access is restored Be sure to change your Wi-Fi passwordto avoid repeated problems. Rules for creating a strong password for DSL-2640U:

  • 🔹 Length: minimum 8 characters (optimally 12+).
  • 🔹 Combination: uppercase + lowercase letters + numbers + symbols (For example, #, $, &).
  • 🔹 Avoid: birth dates, names, dictionary words, repeating sequences (12345678, qwerty).

How to change your password:

  1. Log in to your admin panel (192.168.1.1).
  2. Go to Wireless → Security.
  3. In the field Pre-Shared Key Enter a new password.
  4. Click Save Settings (or "Save").
  5. Reconnect all devices with the new password.

Recommended encryption types:

  • 🔒 WPA2-PSK (AES) — optimal balance between security and compatibility.
  • 🔒 WPA3-PSK - if your devices support (on DSL-2640U (rarely encountered).
  • ❌ WEP - outdated and unsafe, do not use!

7. Troubleshooting: Why doesn't Wi-Fi work after a reset?

If Wi-Fi doesn't turn on or devices don't connect after resetting or changing the password, check the following:

  • 🔹 Is Wi-Fi turned on? In some firmware versions, wireless networking is disabled by default after a reset. Go to Wireless → Basic Settings and make sure the box is checked Enable Wireless costs.
  • 🔹 Correct region? In the settings Wireless your region must be selected (for example, Russia), otherwise some channels may not work.
  • 🔹 IP address conflict? If the router issues 192.168.0.1, and your computer is configured to 192.168.1.X, connection will be impossible. Check your PC's network settings.
  • 🔹 Channel congestion? If there are many networks nearby, the router may automatically select a congested channel. Manually select the channel 1, 6 or 11 (they intersect the least).

If the indicator Wi-Fi If the light on the router is off or flashing red, the problem may be hardware related:

  • 🔹 The Wi-Fi module is damaged (repair required).
  • 🔹 The antenna is faulty (check the connector connections).
  • 🔹 Chipset overheating (let the router cool down for 10-15 minutes).
Is it possible to find out the Wi-Fi password without resetting the settings?

Yes, if you know the login/password for the admin panel. Log in 192.168.1.1, then to the section Wireless → Security — there will be a field with the current password. If the password is displayed as asterisks, use the browser's code inspector (right-click → "Inspect Code") to view it.

What should I do if my router doesn't connect to the internet after resetting it?

Most likely, the connection to the provider is not configured. Go to WAN (or Internet) and check:

  • 🔹 Connection type (PPPoE, Dynamic IP, Static IP).
  • 🔹 Login/password from the provider (for PPPoE).
  • 🔹 VPI/VCI parameters (for ADSL, usually 0/35 or 8/35).

This information should be included in your contract with your provider. If not, call support.

How to update firmware on DSL-2640U?

A firmware update may resolve Wi-Fi or security issues. Download the latest version from official D-Link website (Support section). Next:

  1. Log in to your admin panel (192.168.1.1).
  2. Go to Tools → Firmware.
  3. Click "Browse", select the downloaded file and wait for it to complete (do not turn off the router!).

⚠️ Do not interrupt the update process, as this may damage your router.

Can the DSL-2640U be used as a signal repeater?

Technically yes, but with some caveats. This router does not support the mode. Repeater (repeater) at the firmware level. However, it is possible:

  • 🔹 Connect it via cable to the main router and distribute Wi-Fi as a separate network.
  • 🔹 Use alternative firmware (for example, OpenWRT), if they support your device revision.

For a repeater, it is better to buy a specialized device (for example, TP-Link RE605).

Why does my DSL-2640U frequently overheat and shut down?

This model is known for overheating issues due to a weak cooling system. Solutions:

  • 🔹 Place the router in a ventilated area (not in a closet or on a radiator).
  • 🔹 Place a stand underneath it for better air circulation.
  • 🔹 Disassemble the case and clean it from dust (if you have experience).
  • 🔹 Reduce the load: disable torrents, limit the number of connected devices.

If the router turns off under even the slightest load, the capacitors on the board may have failed (soldering is required).

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