Posted: Mon Sep 14, 2009 12:16 Post subject: how-to un-brick the wrt600n via serial
I fixed mine so wrote a how-to, about post 12....
Hi!
i have come to the conclusion that my 600n is bricked and i cannot recover via tftp, so i am going to attempt through serial to clear the nvram.
I however i have no idea how to go about doing this, has anyone else done this? i have all the equipment i just don't know where the serial port is on the 600n, i read somewhere that it was accessible through the internet port? if so do i just wire up an ethernet to the rx tx? or is there more to it than that?
I have started to disassemble the unit but don't know what i am looking for on the board, so any pointers??
thanx!
Dan
Last edited by gobbledigook on Tue Sep 22, 2009 12:15; edited 3 times in total
ZeroPain had a guide with photos but it seams to be erased from his wiki (link is empty now). But you can look at this thred I use. there is hardware discution _________________ wrt54gs v1.0 BS build 14289 mini
wrt600n v11 eko build 14853 mega...
Fonera FON2200
Motorola WR850G v2 BS build 14289 mini
There is a whole thread on serial recovery linked in note 6 of the peacock thread. If that doesn't work, and your router is not recoverable, contact Barryware by PM. _________________ SIG:
I'm trying to teach you to fish, not give you a fish. If you just want a fish, wait for a fisherman who hands them out. I'm more of a fishing instructor.
LOM: "If you show that you have not bothered to read the forum announcements or to follow the advices in them then the level of help available for you will drop substantially, also known as Murrkf's law.."
There is a whole thread on serial recovery linked in note 6 of the peacock thread.
i have fo9llowed the peacock thread and it links to a whole thread on serial recovery, however neither mention how to connect to the serial on the board?
Just play with it...
You can't assume that pin1 is same on all routers... It should +volt, -volt and 0volt. (or only 2) ZeroPain have played with it and get it working. Use right bit rate (I think it was 9600bits) otherwise you get screen with mass dummy text.. _________________ wrt54gs v1.0 BS build 14289 mini
wrt600n v11 eko build 14853 mega...
Fonera FON2200
Motorola WR850G v2 BS build 14289 mini
Joined: 26 Jan 2008 Posts: 13049 Location: Behind The Reset Button
Posted: Mon Sep 14, 2009 17:58 Post subject:
gobbledigook wrote:
Quote:
There is a whole thread on serial recovery linked in note 6 of the peacock thread.
i have fo9llowed the peacock thread and it links to a whole thread on serial recovery, however neither mention how to connect to the serial on the board?
thats what i'm after:)
Normal Linksys serial pinouts are vcc rx tx n/c and ground.
This device it has been posted that it is n/c rx n/c n/c tx. My guess is that the three n/c's, one is vcc, one is ground, and the other indeed is a no connection.
This will be easy to determine with a volt and an ohm meter.
Pin one should be vcc. Test it from pin 1 to ground with a volt meter. If you have 3.3V.. There is vcc.
Find ground with an ohm meter from ground to the other pins.. Zero ohms, means you found the ground pin. tx & rx you will have to experiemnt with. I mix em up all the time cause my ttl shifter has tx & tx backwards.. The maker thought they were doing me a favor.. It just makes me mix them up..
The zeropain wiki page's links are now dead so no help there. _________________ [Moderator Deleted]
ok, thanx for the help, I was a bit dubious about poking around with a multi-meter in case i made matters worse.
what i have found with my meter is below, if i just look for voltage and hold the positive on the holes marked 3.3, then i get a reading of 3.3v when the neg is held on the holes marked gnd
Code:
j13
3.3 o o 3.3 |
o o 3.3 |
o o gnd | flashing LED's here
3.3 o o gnd |
o |
so assuming the top left is number 1 think pins 3 and 5 must be rx and tx? what do you think?
i can't test further cause i made my own serial to ttl, unfortunately i couldn't find the right signal diode so i am waiting for it to come from fleabay:)
Joined: 26 Jan 2008 Posts: 13049 Location: Behind The Reset Button
Posted: Mon Sep 14, 2009 19:21 Post subject:
I found this.. The zeropain wiki has had the pics deleted. I got this from a cached page. It has tx, rx, and ground. One of the holes will be 3.3vcc. You will need that depending on your ttl adapter.
n/c = "no connection" _________________ [Moderator Deleted]
_________________ SIG:
I'm trying to teach you to fish, not give you a fish. If you just want a fish, wait for a fisherman who hands them out. I'm more of a fishing instructor.
LOM: "If you show that you have not bothered to read the forum announcements or to follow the advices in them then the level of help available for you will drop substantially, also known as Murrkf's law.."
Thanx for the pic!! i didn't even think of cached pages... d'oh!
my adapter is homemade, i had most of the stuff but am waiting on one thing to complete the board, i have made it with its own power supply so shouldn't need the one from the router, unless it becomes necessary. i have also taken an idea from another thread which i forget now (i've read sooo many!!) and used a headphones socket which i will use to connect to the routers serial, and leave in place. I may even make a hole for it and glue it in. that way if i need to go through this again i can simply plug in:)
when i am done i will post a full pics and diagrams as a reminder to myself as much as others:)
Posted: Tue Sep 22, 2009 12:13 Post subject: how to unbrick the wrt600n via serial
Hey!
I successfully un-bricked my 600n via serial, it took a while to compile all the correct information on how to actually do this so I thought I would write it up with some pictures for future ref :)
what you need:
some spare wires/cabling
Max232 rs232 serial to TTL converter like this one. Or you could have a go at making your own, a schematic here although mine didn't work:(
a soldering iron + some solder
some pin type things to fix to the board (optional)
so to begin with you need to actually get into the router. This is more difficult than it sounds as after careful inspection I could not find any visible screws holding it together. In fact the top and bottom cover simply pull up at the back, if you consider the bit with all the lights to be the front, and then slides out - front to back. next the front panel which covers the lights needs to come off too, for this you need to push together the four clips at each corner, top and bottom and slide it off.
Next on the underside of the router are four screws one in each corner, these need to be removed in order to get to the board. When removing these final bits of casing you will need to forcefully prize them from the components on the board which they are stuck to. This leaves you just the board. The serial part is toward the front of the router, circled in red in the pic below.
I attached some pins to it in order to not damage the board with several attempts at soldering the cables in the right place! after this it is simply a matter of attaching some wires correctly, see diagram above found by Barryware, and attaching these to your Max232 serial device. If you look at my pic below you will see that the green wire is teh 3.3v. I used Putty, cause I like it, to chat to the router with, start putty, and select connection type "serial" above that enter "speed" as 115200 and hit connect. Thanx to Barryware for the full serial settings:
Barryware wrote:
Baud 115200, 8 bits, no parity, 1 stop bit... I'm not sure about flow control.. "None" as well as "xon/xoff" works for me.
Then plug the power to your router in and see the screen fill with start-up stuff :)
press CTR+C to interrupt the start-up bit and you get a CFE> prompt
issue 2 commands:
Code:
nvram erase
Code:
reboot
it took me a couple of goes to get this to work, my main mistake was trying to daisy-chain the command. When I rebooted and went to the routers config page I was greeted with the prompt to change user and password as if I had just installed dd-wrt :)
After my sigh of relief, I stole another persons idea and fixed an audio socket into the back of my router attached to the Rx Tx so if I do it again I don't have to take it to bits!! I have an external 3.3v power supply.
Now put your router back together again, and slap yourself on the wrist for being sooooo stupid to brick it in the first place!
Hope this helps!
Dan
router-pic_005.jpg
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pic of my amazing engineering ;)
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router-pic_004.jpg
Description:
close up of the serial with pins soldered in and wires attached
