Flash TM-AC1900 to ASUS RT-AC68U to use AiMesh

Image for post
Image for post

T-Mobile router TM-AC1900 is a cheap alternative model of Asus RT-AC68U. But it is not supported by Asus officially, i.e, it is unable to upgrade to its latest firmware version. To use Asus’s latest fancy feature —Asus AiMesh. To utilize Aimesh, it needs to flash its bootloader to Asus CFE 1.0.2.0 and then erase MTD5 partition. After doing that, it is identical with a genuine RT AC-68U.

To achieve this, First to download this file and extract it to a newly created folder. It contains a firmware to downgrade to, a firmware to upgrade to, and an executable file, mtd-write.

  1. The router is coming with the firmware version 3.0.0.4.376.3108 which has ssh option disabled and hidden, after trying to downgrade it to firmware version 3.0.0.4_376_1703 so that ssh can be enabled.

How to downgrade AC-1900 is really a headache.

2. Go to 192.168.29.1 in a web browser
If Mini-CFE webpage won’t load use Asus Restore Utility
If having trouble with this step perform NVRam Reset and try #2 again
not working in my case

Follow this instruction, it will work:

2). powering on3). waiting a few seconds for fast blinking lights4). releasing the WPS and wifi buttons, but still holding down reset,5). as soon as 192.168.29.1 started answered pings, quickly visiting http://192.168.29.1/ to open the mini CFE uploader,6). submitting the 1703 firmware, and waiting for upload success message7). finally releasing the reset button. The rest of the how-to worked just fine.

T-Mobile has made it harder to modify the router, but it’s still possible.

2. Log in to router (admin:password), enable ssh in the administration page

Go to Administration > System > Enable SSH > Yes > Apply

3. using putty ssh to the router, copy bootloader cfe out:

Then use scp to copy it out.

4. Copy original_cfe.bin to a local drive

5. Upload original_cfe.bin to https://cfeditor.pipeline.sh/ > Select 1.0.2.0 US AiMesh as Source CFE for Asus/Merlin builds, (1.0.2.5 recommended for DD-WRT or Tomato) > Download the new .bin > rename it to new_cfe.bin

Image for post
Image for post

6. Upload new_cfe.bin & mtd-write & FW_RT_AC68U_30043763626.trx to router through WinSCP

7. In Putty type:

Note: If did not input the correct command format, mtd-write gives the wrong usage info, DON’T follow it, it is wrong.

  • Actually write the ASUS CFE version and overwrite the T-mobile one by typing:

before flash:

After flash ASUS CFE, the output looks like this:

admin@(none):/# nvram get HW_ver
170
admin@(none):/tmp/home/root# nvram get clkfreq
800,666

8. Perform NVRAM Reset, wait for reboot <5 mins

After flash asus firmware 376, the default gateway IP changes to 192.168.1.1
username:password is now: admin:admin

9. ssh to the switch, remove mtd5 partition, otherwise, Asus will not let you upgrade to its 384 firmware since TM-AC1900 is not official supported by Asus and Asus added a firmware check.

Next, you can download official Asus firmware from its website, and upgrade to latest version to enjoy AiMesh. After flash to 384.xx,

To check if your on CFE 1.0.2.0 or CFE 1.0.2.0 US AiMesh
As you will notice, doing this command(found from years ago):

It just says 1.0.2.0 not anything about AiMesh.

To check Version verification, use Putty to telnet into router. Click the picture bottom of. this post

“If it returns “odmpid=RT-AC68U” odds are high you have installed the correct one(1.0.2.0 US AiMesh).
If is says “odmpid=ASUS”, that’s the non-AiMesh one.”

— — -
How do I double check the MTD5 signature
Do you think you didn’t do the MTD5 commands correctly
Lazymocha’s Guide doesn’t explain to do the last two MTD5 commands on firmware 384.xxxxx (preferably 384.20308).
If you didn’t read correctly about the MTD5 command step above, you might not have had the last 2 MTD5 commands effectively done.

To check this, once again, putty in and do the following command:

A “real” RT-AC68U has absolutely nothing in /dev/mtd5 except it is filled with 0xff. You should see no result for the command output.(seen in green)

I did see weird things:

If you do see some misc strings, there’s something in mtd5 and you should execute the commands to wipe it when on firmware Version 384.xxxxx

After this, everything works like a charm. You can sit at the back yard, enjoy a cup of cafe and web browsing at same time offered by Asus AiMesh now.

Reference:

Written by

自由撰稿人,时评人,平等公义追求者

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store