Q: Hi everyone,i have a two band tp-link router but mau macbook dosent connect to 2.4ghz band evevn dont find it.what shoul i do?

Hi Ash94sh,

Thanks for contacting Apple Support Communities. 

I understand that your MacBook isn't connecting to the 2.4ghz band on your TP-LINK router.  Use the article Recommended settings for Wi-Fi routers and access points, specifically, these sections: 

Follow these steps first

Before you change your settings, follow these steps:

• Make sure that your Wi–Fi router's firmware is up to date. If you're using an AirPort base station or Time Capsule, follow these steps.
• Make sure that all Wi–Fi devices you want to use support the settings this article recommends.
• If possible, back up your Wi–Fi router's settings.
  If necessary, refer to the product documentation or manufacturer's website.
• Forget or remove the Wi-Fi settings for your network from any devices that connect to your Wi-Fi router. This will prevent the devices from attempting to connect to your network with the old configuration. You'll need to reconnect these devices to your network when you've finished applying the new settings.

Configure all Wi–Fi routers on the same network with the same settings. Otherwise, devices could have difficulty connecting to your network, or your network could become unreliable. On dual-band Wi–Fi routers, configure both bands to have the same settings unless otherwise noted below.

You can configure an AirPort Base Station with AirPort Utility. If you have a different router, refer to the manual or to the manufacturer's website to learn how to change the settings.

Use the settings below for best performance, security, and reliability.

2.4 GHz channel width

Channel width controls how large a "pipe" is available to transfer data. However, larger channels are more subject to interference and more prone to interfere with other devices. A 40 MHz channel is sometimes referred to as a wide channel, with 20 MHz channels referred to as narrow channels.

Set to: 20 MHz

Details: Use 20 MHz channels in the 2.4 GHz band. Using 40 MHz channels in the 2.4 GHz band can cause performance and reliability issues with your network, especially in the presence of other Wi-Fi networks and other 2.4 GHz devices. 40 MHz channels might also cause interference and issues with other devices that use this band, such as Bluetooth devices, cordless phones, neighboring Wi-Fi networks, and so on. Note that not all routers support 40 MHz channels, especially in the 2.4 GHz band. If they are not supported, the router will use 20 MHz channels.

Get more information in our OS X user manual below. 

Connect to the Internet using Wi-Fi

Have a great day!