Posted: Fri Jan 17, 2020 2:29 Post subject: Can't downgrade WRT1900AC V2 w/stock firmware 188.8.131.52401
Given the lack of activity on this thread, perhaps my post will get no replies, but maybe it will be worth it to someone who is contemplating buying a WRT1900AC V2.
TLDR: Don't buy the V2 hardware!
I've been poring over this forum while working to get DD-WRT on my WRT1900AC V2, but I've found no love. I've got the stock firmware, version 184.108.40.206401.
First I flashed some fairly current 2019-2020 builds and the router failed to boot (flashing LAN, no power light). I tried the special one from 4/2016 and that didn't work either.
I saw the recommendation to downgrade firmware, but that seems to mainly be for people V1 hardware given the version numbers. I tried it anyway, though and managed to downgrade just one version number and now I can't get any lower. I have every version all the way back to the original 2015 version and the router will pretend to flash it, but no dice.
After the downgrade, I tried flashing a whole bunch of DD-WRT versions all the way back to the first one for V2, but still no dice, but I no longer got fail boots. Now it just boots straight back into the stock firmware every time.
I saw the information about switching partitions using telnet, but there is no option to turn on telnet in the firmware I've got. I've been though it a bunch of times and I can't find it anywhere. It also isn't turned on by default.
So... I seem to have come to the end of the road.
Is there anyone out there that may have some new light to shed on my very dark situation?
Disconnect the WAN, disable any security software or firewall, disable your wireless client adapter to make sure the flash goes over the Ethernet cable connected to LAN and finally try a different browser. Waterfox Classic, Pale Moon, Portable Legacy 45 or 52
Oh, and make sure you are flashing with factory-to-ddwrt.bin =).
If you are having problems with the initial flash being too large, go back to first build of 2019 or 2018.
I actually tried all of that before I posted (not the waterfox). Yes, even the earlier versions. I actually tried the first of the year versions back to 2016, just because I'm superstitious. I tried a bunch of others too.
It turns out that it was actually a router problem.
Originally, not being able to flash DD-WRT, I had downgraded from 220.127.116.11766 to 18.104.22.168401 because I saw that a downgrade had helped people with the V1 hardware. I would have gone lower, but couldn't because earlier versions wouldn't overwrite.
In a fit of despair, I decided to try upgrading back to the newest stock firmware but I found that I couldn't do that either! It didn't matter what browser, cache clearing, history dumping, reset pushing, or triple-rebooting I did.
Finally, I contacted Linksys and they gave me a "Recovery Reset" procedure which is similar to, but different than the triple-reset I've read so much about:
1) Turn Router on and off.
2) Turn router on, let power LED flash twice, turn router off.
3) Repeat 1 & 2 three times, then allow it to boot normally the 4th time.
4) Once booted, factory reset it by pressing the reset button until the power LED flashes.
Once I did all this, I was able to upgrade back to the latest stock firmware.
Given the trouble I had initially trying to flash DD-WRT on this version (a bunch of fail-to-boots), I've decided to try OpenWRT for the moment and swap over for DD-WRT if I find I don't like it.
It's weird because I've been using DD-WRT for at least 15 years but right now, I just need a router that works.
Due to the flash layout of these routers it's damn near impossible to brick. You likely just need a usb to ttl serial cable that I linked above if you can't manage to power toggle the router into a failover to the other partition (described above).
Anyway, you told me nothing about what you've done so far so all I can say is hard reset hold 10 seconds etc.
Is your router wrt1900ac (v1) or wrt1900acv2? The Model No. is on the bottom of the router.
Which builds have you attempted to flash? Are you flashing from stock Linksys web interface with factory-to-ddwrt.bin?
Does the router respond to 192.168.1.1 from a browser or telnet?
Posted: Sat Jan 25, 2020 18:54 Post subject: linksys wrt 1200 av v2 nvram erase with telnet
I had to reset my linksys wrt 1200 v2 today as vpn client stopped working. I resetted on telnet with erase nvram.
It worked but i noticed it only resetted the partition i was on. The other partition wasn't resetted. I thought it would reset both partitions?