Here’s the simplest method I know of for flashing a TM-AC1900 to a RT-AC68U. I’ve tested it myself and can confirm it works. This is a free resource, if you have questions or need assistance leave a comment below and someone may help, but please don’t use my contact form it is meant for paying customers.
All responsibility for anything that happens is yours.
Update 12/23/2017: This guide has been rewritten past step 15 and old comments will reference the wrong steps. To see the original guide see this archived page.
How to flash AC1900 to AC68U:
- Install WinSCP, Putty, and a file archiver (click this link for ez). Install the Asus Restore Utility, mirror.
- Create a folder on your desktop, name it “router”.
- Download this file and extract it to the newly made router folder. It contains a firmware to downgrade to, a firmware to upgrade to, and mtd-write.
- Set static IP for PC.
start > run > ncpa.cpl > double click Ethernet > properties > IPV4 >
Subnet: Default (255.255.255.0)
- Place router into Recovery/Restore mode
Hold reset button 10 seconds
Power off router (keep holding reset)
Wait 10 seconds, keep holding reset
Power on router holding reset for 10 more seconds
- Go to 192.168.29.1 in a web browser
If Mini-CFE won’t load use Asus Restore Utility
- Flash TM-AC1900_220.127.116.11_376_1703-g0ffdbba.trx
- Wait for reboot <5 mins – WiFi lights will turn on when boot is complete
- Log in to router (admin:admin or admin:password)
- Go to Administration > System > Enable SSH > Yes > Apply
- Open Putty and WinSCP and connect them to 192.168.29.1 using a admin:admin or admin:password
Tip: In WinSCP select SCP as file protocol, in Putty SSH
- In putty type:
cat /dev/mtd0 > original_cfe.bin
- In WinSCP refresh the window on the right side and note that original_cfe.bin is present
- Copy original_cfe.bin to a local drive
- Upload original_cfe.bin to https://cfeditor.pipeline.sh/ > Select 18.104.22.168 US as Source CFE > Download the new .bin > rename it to new_cfe.bin
- Upload new_cfe.bin & mtd-write & FW_RT_AC68U_30043763626.trx to router through WinSCP
- In Putty type:
chmod u+x mtd-write
- In Putty type:
./mtd-write new_cfe.bin boot
- In Putty type:
mtd-write2 FW_RT_AC68U_30043763626.trx linux
- Perform NVRAM Reset, wait for reboot <5 mins
a. Power off router
b. Wait 10 seconds
c. Press and hold WPS button
d. Power up the router and continue to hold WPS button for 15-20 seconds
- Reset PC IP back to default
- Log in to router using 192.168.1.1 and the router is now an AC68U with 64MB jffs
- Feel free to flash AC68U builds from Asus, Merlin, Tomato, DD-WRT, etc or to “overclock” it using instruction below.
This method has been compiled from three points of information:
- Snbforums.com flash instructions: flashInstructions_cDec04_16.pdf
- Bootymonger from slickdeals: slickdeals.net
- Wherever I found https://cfeditor.pipeline.sh/
- Comment from Albert Lee (thanks!)
- If you have a fast connection you may benefit more from Merlin or official builds as they have enabled hardware acceleration which allows the router to download and upload at higher speeds.
- You may check router cpu speed at http://192.168.1.1/Tools_Sysinfo.asp
- If the 30/30/30 reset doesn’t work try this:
1. power off device
2. hold reset 20 seconds
3. power on device holding reset until power light blinks slowly
The T-Mobile version of the router comes clocked at 800mhz. Overclock it to 1ghz with these instructions (only tested with Merlin build):
- Log in to router using putty and type the following commands
- nvram get clkfreq
- nvram set clkfreq=1000,800
- nvram commit
After reboot the router will be overclocked.