If your TL-MR3020 router is bricked with the following symptoms, most likely you can use this method to recover it.

1. Ping the router without problem
2. Telnet connection failed
3. SSH connection failed

Solution:

1. Put the router switch to AP mode
2. Turn on the router power
3. Push and hold the "WPS" button
4. When the WPS Led flash slowly, switch on AP mode to 3G mode. The LED should flash quicky.

Now, you can Telnet to router

Erase the root data

Login to the router via telnet and enter the following command. Most likely your router is now recovered. 

Continue following procedures if it is still not working.

Copy firmware to router

• Login to router via telnet and change the password in order to enable SSH

• Copy the OpenWRT firmware to the router /tmp folder. I personally like and use WinSCP.

Upload the firmware to router

SSH to router and write the firmware to router. Where code.bin is your OpenWRT firmware file. 

Reboot the router and your router should be working now. If all the above methods is not working for you, then you should go for Serial Console method to recover the bricked router.