[zackw]

I have what I believe is an WRT1900ACv1 (it has four antennas, but it doesn't say v2 on the front panel, the serial number starts 13J1, and I see a fan through the holes in the black part of the top cover). It's currently got the Linksys stock firmware on it. I tried to reflash it with factory_to_ddwrt.bin last weekend, using the Linksys firmware update GUI. The GUI reported a successful reflash but, when the router rebooted, it only came up as far as a blinking white power light - in particular, the "internet" light did not turn on at all - and then rebooted itself again. This repeated three times and then it reverted to the stock firmware.

Can anyone advise what might be wrong and how I should proceed? I do not have the special cable for connecting to the serial port (and would prefer not to have to take the router apart, anyway).

I don't know the exact build number but I still have the .bin file, if someone can tell me how to extract the build number from it I will post it. The file is 40,501,248 bytes long and its sha256 checksum is 216883babe1caa7c27d70d40ec5e3021cc4b2b2286b530deaf3412e1b8f2eac7.

[kernel-panic69]

When and from where did you download the firmware image? I don't think there is a way to extract the information from a hex editor.

[WENED]

Just a quick observation. The file you used was 40k+ which indicates that it is one of the builds that only could be installed on partition 1 as it was too large for partition 2.
This problem has long since been corrected by BS and recent builds all work well on the 1900 V1's.
I would suggest you use a build more recent (current)
ftp://ftp.dd-wrt.com/betas/2020/
Your experience is exactly what happened with these oversize builds.

[kernel-panic69]

I wasn't going to state the obvious.

[SurprisedItWorks]

See "Cliff Notes" post https://forum.dd-wrt.com/phpBB2/viewtopic.php?t=311117 for how to flash a WRTwhatever router, including where to find the (beta) firmwhere images. Don't use the obsolete, unmaintained "router database" to choose an image. Look in the Marvell forum for recent "new build" threads, and if no one is reporting trouble with that particular router, just try the latest build.

[zackw]

According to my browser history, I downloaded the image on July 4 from https://download1.dd-wrt.com/dd-wrtv2/downloads/betas/2019/08-06-2019-r40559/linksys-wrt1900ac/factory-to-ddwrt.bin , which I believe was indeed linked from the "router database". I see that the images in the betas directory are considerably smaller, so I'll give one of those a try this weekend (not going to mess with my internet access, that i need to do my job, during the workweek :P ) Thanks for the tip.

(It's unfortunate that the prominently advertised "router database" is not being kept up...)

[SurprisedItWorks]

Indeed, 40559 has actually been an especially troublesome build. The forums are getting several enquiries per week about 40559 disasters, always traceable to the database. And we all agree with you about the database. Many people begging to correct this situation hasn't accomplished much, so all we can do is try to catch the problems in the forums.

[kernel-panic69]

I'm about @#$%^&*! tired of seeing the number 40559. We put a @#$%^&*! disclaimer on the router database landing page, it's getting completely @#$%^&*! ignored and I'm about @#$%^&*! over it. We have no control over the site admins' not updating the router database.