Posted: Sun Mar 17, 2024 19:15 Post subject: Asus N66U soft brick in recovery mode
I was downgrading from last build r55363 to r46885, reason being worse wifi coverage and was unable to tweak for whole day from advanced menu.
so I 'Restore to Factory Defaults' and on next boot up downgrade to r46885 selecting "reset factory defaults after flash". Next boot gui doesn't show up. hard reset. nothing happens.
so I start recovery process, which I have successfully done before. First I used asus firmware recoevery tool, it was failing on 2% to 40%. then went web interface running mini server uploaded either big package or asus stock firmware RT-N66U_3.0.0.4_382_52272-g73d3ea2.trx, I notice right there size of upload was mismatching, this has been occurring since then on all the fw I tried dd-wrt, tomato, merlin, asus-stock. Also ttfpd gave me md5 that was not matching my firmware md5. If I remember size was matching last time I used it successfully.
After I flash firmware power button stays on before reboot.
all successful but mismatched firmware uploads end up in recovery mode on power cycle, hard reset.
before-after tftp
after power cycle tftp.png
what next steps can I take without jtag / serial ?
You're probably going to have to resort to serial if firmware restoration tool, TFTP, or miniCFE web server recovery do not work. Selecting reset after defaults in DD-WRT webUI was a no-no, most likely.
Joined: 26 Mar 2013 Posts: 1858 Location: Hung Hom, Hong Kong
Posted: Mon Mar 18, 2024 14:49 Post subject: Re: Asus N66U soft brick in recovery mode
Ocheabos wrote:
so I start recovery process, which I have successfully done before. First I used asus firmware recoevery tool, it was failing on 2% to 40%. then went web interface running mini server uploaded either big package or asus stock firmware RT-N66U_3.0.0.4_382_52272-g73d3ea2.trx, I notice right there size of upload was mismatching, this has been occurring since then on all the fw I tried dd-wrt, tomato, merlin, asus-stock. Also ttfpd gave me md5 that was not matching my firmware md5. If I remember size was matching last time I used it successfully.
Did you download Asus' factory firmware using FTP? Did you forget to use binary mode?
The CFE Mini Web Server should be quite resilient to crashes, unless you damaged it by improper flashing of DD-WRT. _________________ Router: Asus RT-N18U (rev. A1)
Drink, Blink, Stretch! Live long and prosper! May the Force and farces be with you!
Joined: 13 Aug 2013 Posts: 6870 Location: Romerike, Norway
Posted: Mon Mar 18, 2024 16:54 Post subject:
1-Have a firmware file available, ending with the extension .trx
2-Power down the router.
3-Remove USB memory devices (if any).
4-Press and hold the reset button, at the same time power up the router.
5-Wait for slow flashing Power LED.
6-Release the reset button.
7-Set your computer to a fixed IP address, such as 192.168.1.100 / 255.255.255.0.
8-Hardwire your computer to the router.
9-Open a Terminal window and make sure you can ping 192.168.1.1
10-CD into the directory where the firmware file exists (see step #1 above).
11-Run these commands from the Terminal prompt, using the correct firmware filename in the "put" command:
tftp
tftp> connect
(to) 192.168.1.1
tftp> binary
tftp> put <filename>.trx
Sent xxx bytes in yy seconds
tftp> quit
12-Give the router about 30 minutes to process the firmware image you've just sent it.
13-Access the router at the default IP address 192.168.1.1 and admin/admin
14-Manual configure the router again (do NOT load an old configuration backup file).
Selecting reset after defaults in DD-WRT webUI was a no-no, most likely.
Weird since it's such a simple task, but I guess it might've reset to defaults earlier it should've, before properly flashing (maybe 10mins?)
Depends on CFE version installed on the router. If DD-WRT thinks it's 64k and it's only 32k, you erased part of the flash that you shouldn't have. _________________ "The woods are lovely, dark and deep,
But I have promises to keep,
And miles to go before I sleep,
And miles to go before I sleep." - Robert Frost
"I am one of the noticeable ones - notice me" - Dale Frances McKenzie Bozzio
Depends on CFE version installed on the router. If DD-WRT thinks it's 64k and it's only 32k, you erased part of the flash that you shouldn't have.
I think it was 64k on 1.0.1.4
Per Yngve Berg wrote:
tftp> put <filename>.trx
Sent xxx bytes in yy seconds
tftp> quit
12-Give the router about 30 minutes to process the firmware image you've just sent it.
13-Access the router at the default IP address 192.168.1.1 and admin/admin
14-Manual configure the router again (do NOT load an old configuration backup file).
I used linux to send firmware in binary and it uploaded exact amount of bytes as local firmware but it didn't work . tried this on latest ddwrt and stock fw.
Haven't given it 30mins only 10-15 but once it came back with ttl=100.
from webserver it still got corrupted and byte offset was 63.
Also clicking "restore nvram values" gave "command completed", but didn't reboot, not sure if it's intended, but "reboot" button did.
