Serial flash help - bricked ea6900

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ghostivv
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Joined: 01 Jul 2016
Posts: 9

PostPosted: Mon Jul 04, 2016 8:23    Post subject: Serial flash help - bricked ea6900 Reply with quote
Finally managed to brick EA6900. Ping is fine on TTL=100 but tftp failing with timeout error. Tried every trick posted here and decided to go with serial flash route. Opened the router and first relief is header pins are there so no need for soldering. Now problem is no labels on them so which pins are what?

Also I can't seems to find guide on commands for serial flash. Can any kind soul pls post either link or detail step by step for novice like me Smile. I've got both stock Linksys and initial ddwrt fw and not sure which is recommended.

Thanks
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ghostivv
DD-WRT Novice


Joined: 01 Jul 2016
Posts: 9

PostPosted: Tue Jul 05, 2016 22:50    Post subject: Reply with quote
I found the pin layout posted by BrainSlayer:
Quote:

v+, none, tx, none,rx,gnd

the white connector on the board


I connected the cables (layout looking from front of router) and no response. Later I swapped gnd and tx, powered on router and managed to see booting process. But CTL-C, ESC, SPACE, all these failed to halt booting.



routerboot1.jpg
 Description:
initial Boot
 Filesize:  177.99 KB
 Viewed:  13380 Time(s)

routerboot1.jpg


ghostivv
DD-WRT Novice


Joined: 01 Jul 2016
Posts: 9

PostPosted: Tue Jul 05, 2016 22:54    Post subject: Reply with quote
anything not normal?


routerboot2.jpg
 Description:
 Filesize:  114.36 KB
 Viewed:  13376 Time(s)

routerboot2.jpg


notorious.dds
DD-WRT User


Joined: 24 May 2012
Posts: 376
Location: Michigan

PostPosted: Thu Jul 07, 2016 7:32    Post subject: Reply with quote
Check your serial adapter and the wire connections. The adapter should be of the 3.3V variety. Also, in my experience, not all adapters are created equal. I had this experience with a modified CA-42 cable and was never able to stop the boot process. Upon switching to a CP2102 Breakout adapter, everything worked as desired.
ghostivv
DD-WRT Novice


Joined: 01 Jul 2016
Posts: 9

PostPosted: Fri Jul 08, 2016 11:28    Post subject: Reply with quote
SUCCESS!!! Mr. Green and currently custom CFE on xVortex.

I'd CP2102 which worked with other modem but decided to order PL2303HX variant from ebay. Only cost £2.33 and arrived in 2 days (UK mainland). There's a driver issue on Windows 8.1 and need 1.2.10. Once setup and putty output, followed DDWRT serial recovery wiki with linksys tftp application.

-ctheader was an invalid switch. Typed "help flash" (without quotes) to confirm and other options which was -noheader.

Anyway it was good and big relief to see command output "LINKSYS" and login page Smile. One more thing, I also had to manually put gateway (192.168.1.1) to initially access setup page.
amikot
DD-WRT Novice


Joined: 30 Sep 2018
Posts: 47
Location: United Kingdom

PostPosted: Sun Dec 16, 2018 12:20    Post subject: Reply with quote
Hi, I think I'm in the same situation now as you was, so I have an question. What firmware did you flashed into bricked ea6900? And how did you installed xvertex on it? Thanks Smile
_________________
Bible in short: Don't be religious. Just love God and follow Jesus Smile
amikot
DD-WRT Novice


Joined: 30 Sep 2018
Posts: 47
Location: United Kingdom

PostPosted: Tue Dec 18, 2018 14:36    Post subject: Reply with quote
I have just question what should be flashed under what names/partitions.
Partitions of EA6900 are named different than it is in DD-WRT serial-recovery guide.
Thanks.
egc
DD-WRT Guru


Joined: 18 Mar 2014
Posts: 12881
Location: Netherlands

PostPosted: Tue Dec 18, 2018 16:50    Post subject: Reply with quote
The stock linksys partition scheme should be something like:
root@Linksys EA6900:~# cat /proc/mtd
dev: size erasesize name
mtd0: 00080000 00020000 "boot"
mtd1: 00100000 00020000 "nvram"
mtd2: 01d00000 00020000 "linux"
mtd3: 01b60000 00020000 "rootfs"
mtd4: 02100000 00020000 "linux2"
mtd5: 01fc0000 00020000 "rootfs2"
mtd6: 04000000 00020000 "ddwrt"

Boot is where the CFE sits, Linux and Linux2 is for the firmware (dual boot setup).

Have a look in the EA6700 thread there should be something about serial recovery there

_________________
Routers:Netgear R7000, R6400v1, R6400v2, EA6900 (XvortexCFE), E2000, E1200v1, WRT54GS v1.
Install guide R6400v2, R6700v3,XR300:https://forum.dd-wrt.com/phpBB2/viewtopic.php?t=316399
Install guide R7800/XR500: https://forum.dd-wrt.com/phpBB2/viewtopic.php?t=320614
Forum Guide Lines (important read):https://forum.dd-wrt.com/phpBB2/viewtopic.php?t=324087
amikot
DD-WRT Novice


Joined: 30 Sep 2018
Posts: 47
Location: United Kingdom

PostPosted: Tue Dec 18, 2018 21:08    Post subject: Reply with quote
From CFE it looks different.
I can't tell you exactly names but they are named like files where first part is nflash0 or nflash1 and after dot there are trx, os, os2

Dd-wrt guide states that flash1.trx should be used as destination in CFE but there is no such of thing.
I will look to ea6700 forums - thanks for advice Smile

PS.
I did search EA6700 forum and found two important information:
1. I should flash nflash1.trx
2. I shouldn't do 30/30/30 as I probably deleted nvram and Can't get it work on stock firmware anymore.

To be honest I think it may be the issue - that someone before did 30/30/30 to this router as it was bricked but as I saw on serial console - linksys firmware did boot but after boot was almost complete every time it crashed.

It is hardware issue or result of cleared NVRAM.

However, I think I flashed exactly that partition (nflash1.trx) with dd-wrt and now it say there is checksum error or something - basically - image is bad.

I just wondering if it may be result of wrong serial interface - Because that what I have - I'm not sure is exactly 3v3 - it may be 5v.
But It works - I have console, no glitches, commands works.
And after all transfer is going trough LAN cable not trough serial.
But maybe it anyway can be wrong.
amikot
DD-WRT Novice


Joined: 30 Sep 2018
Posts: 47
Location: United Kingdom

PostPosted: Wed Dec 19, 2018 15:15    Post subject: Reply with quote
OK. I did tested few more firmwares (including asuswrt), and always the same. Router crashes when boot is almost complete.
In AsusWRT there is moment in the boot when you can hit enter (Serial Console) and have access not to CFE but to proper AsusWRT partition.
So I have that access and can play with settings, but don't know what to do.
If I will exit from console, boot process resumes and after few seconds - crash.
Im not sure, but I think that always few lines before it crashes - I noticed that before it crashes (I'm sure it was in asus-wrt and in both linksys firmwares) something related to eth2 crashes, and in general - it's in area after eth2 setting up, and also there is always also wl0 wl1.
I checked CFE utilities, but all tests that found there router passed. Now I would like to localise the problem. Only option is to disable functionalities somehow, or doing boot in steps, but how to do this?
As I said, I can access linux console on first moments of the boot, so if someone knows how to step boot up in asus-wrt it would be lovely - I would be able to determine what is the problem, and than I could avoid it, or localise broken hardware.
ghostivv
DD-WRT Novice


Joined: 01 Jul 2016
Posts: 9

PostPosted: Wed Dec 19, 2018 19:11    Post subject: Reply with quote
Can't remember now but all the information is onLinksys EA6900 install guide

Just to confirm are you trying serial recovery?
amikot
DD-WRT Novice


Joined: 30 Sep 2018
Posts: 47
Location: United Kingdom

PostPosted: Thu Dec 20, 2018 0:12    Post subject: Reply with quote
Thanks for answer. Yes I'm trying serial recovery. I already tried a lot, but I think it must be hardware. Today I reflowed PCB again in vapour phase oven, but no success nor any change so if it's hardware it's definitely not cold solder.

If I won't repair it tomorrow I will keep it just for spares, as antennas may be useful as radiators as well.

Update:

Today I was cleaning up after this horrible fight and realised myself that power brick supplied by seller is not genuine for this router.
It was 12V 0.2A instead of 12V 3.5A - this is massive difference.
Just after, I took another brick to test, and guess what? Router is OK. It starts, everything works. I don't know how I missed that was just wrong brick. I just assumed that seller gave me whole set as should.
Now I can carry on with upgrading firmware Smile
rahulv21
DD-WRT Novice


Joined: 23 Mar 2020
Posts: 1

PostPosted: Mon Mar 23, 2020 3:43    Post subject: EA6900 Serial Recovery Reply with quote
Hey guys, I need some help.
I wanted to install dd-wrt on my Linksys EA6900. The router was working fine, before I started I decided to perform a factory reset by holding the reset button for 10s, later the router rebooted after reset, then I wasn't able to access the router configuration page. It gives me no ip, the ethernet lights are continuously On(no flashing), power lights is On doesn't flash on boot. I tried to connect my serial Adapter to the white connector,I get no response on putty.
Please help me, my whole internet connection is down.
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