How To Reflash Factory Firmware on the NETGEAR WRN3500L Without A Serial Cable

When you upgrade to DD-WRT on your WNR3500L, you'll find that the new firmware requires a file that ends with the BIN extension, if you ever want to upgrade or change your firmware from that point.

So, if you decide, for example, to revert back to the original NETGEAR firmware - you can't because that firmware has a filename that ends in CHK.

As such, this makes it harder to change back. One way to do it is to use a serial console, but if you don't have one... here's a way to accomplish it in Windows without one.

Fortunately, included in the DD-WRT firmware is an erase utility that will wipe the firmware and allow you to upload a new one.

Here is how it's done.

You first have to Telnet into your router.

To do this simply open up a CMD window and type Telnet 192.168.1.1 (or the location of your router)

You will then need to type in the name and password for your router. If you have not changed it form the original setup, then they would be Name:admin and Password:password.

Once in, you will be shown a prompt that you can use to erase the old firmware.

Type in "erase linux" and it will run and show you its progress.

Once complete, it will again show you a command prompt.

Type in "reboot" and you should see "Connection to host lost"

You can then close this window.

Now we need to put the new firmware on.

Wait about 5 minutes for the router to reboot and then open up a new CMD window.

You will then use TFTP to put the new firmware on the router. This program comes with Windows XP. If you are using Vista, you need to install it.

1. Open the Control Panel and select the Programs entry.
2. From the Programs and Features section, select Turn Windows features on or off.

3. Scroll down the list and place a check in the box next to TFTP Client. Click OK.

4. Give Windows a moment or three to install the tftp client. When its done, exit out of the Control Panel.

Open up a CMD window and type in "tftp -i 192.168.1.1 PUT NameOfFirmware.CHK" as shown below.

Wait a few minutes and you should see "Transfer Successful"

At this point all you need to do is wait. The router will install the firmware and reboot automatically. This could take 5 to 10 minutes.

Once the router is finished booting you can go back into your browser and setup your desired configuration.

Tags: 

Belk
Belk's picture
Thanks for the help with this

Thanks for the help with this one. It got my router up and running with no trouble by following the video tutorial.

ThirstyThursten
ThirstyThursten's picture
Heey Guys,

Heey Guys,

I'm all new to this and I'm Trying and learning atm,

I tried to flash my Ntegear WNR3500L to that DD WRT and I guess something went wrong, I've got a orange power LED NOT blinking just Orange all the time,

when I try the Telnet 192.168.1.1, my CMD says "Busy Connecting..." then comes with "Can't connect to host, on port 23: Connection failed"

So I figured since nothing works, maybe there's just no firmware on it, so I tried the TFTP thing, and it takes very long and then my CMD says "Time-Out Occured"

So please can someone help me what can I do, without using the TTL cable preferly,

I'm sorry if the CMD lines aren't right I have a Dutch machine here so I tried translating it =P

Please help me cause I don't know What to do...

Thanks in Advance

Greets:
Thursten

wyse
wyse's picture
Have you done 30-30-30 resets

Have you done 30-30-30 resets ?

Try again 30-30-30 !!

ThirstyThursten
ThirstyThursten's picture
Thanks man, But Ain't Working

Thanks man, But Ain't Working =(

I tried 3 times but it don't seem to work still an orange Power LED ... =(

Anyone else an idea ??

Pleaaassee ??

Thanks

Greets:
Thursten

ThirstyThursten
ThirstyThursten's picture
HOLD ON Wait A Sec..

HOLD ON Wait A Sec..

=DDD

It's working man (I guess)

The Power LED is Green now and the Wireless LED is now on too (wasn't before)

So Now what ?? can I just log in ??

(It took kinda long before it realized it was being reseted ... xD)

Thanks I'm so Happy =D =D =D

Greets:
Thursten

wyse
wyse's picture
Now you can reflash, using

Now you can reflash, using this topic;

Good luck.

( i think it's really difficult to brick this router. :) )

taekwon3dan
taekwon3dan's picture
@Aaron K Yes. I think it

@Aaron K Yes. I think it was reported recently in tomatousb that in the newer builds, you could flash it directly.

"Kernel 2.6-based builds only (beta23):

  • Fixed Mini build for Netgear routers with 4MB flash (WNR2000v2, WNR3500v2), removed RIPv1/v2 routing from Mini build due to Netgear size restrictions, added JFFS to Mini build to make use of some otherwise wasted flash space.
  • Fixed flashing all supported Netgear routers back to OEM firmware.
  • Media server: removed some rare and obsolete demuxers to reduce size, reduced MiniDLNA memory usage.
  • Minor backports from upstream 2.6 kernel."
Erez
Erez's picture
note:

note:
* under openwrt it would be "mtd erase mtd1"

* if tftping from linux:
tftp
connect 192.168.1.1
binary
put .chk

cheers,
erez.

Joman100
Joman100's picture
Just curious -- has anybody

Just curious -- has anybody ever tried using the firmware recovery utility that ships with the router? I tried it when the router was working fine and it just reported back that my router was functioning correctly and didn't need to be reflashed. I haven't needed to recover and now that I'm using DD-WRT setup exactly as I want I haven't tried since.

nightcrawler
nightcrawler's picture
I had also bricked my router

I had also bricked my router by flashing an K24 update instead of an K26 flashfile. So I googled and found this post.

Well to be short, I have opened the router and had to shortcut the pins.
Be careful with that! Only shortcut the pins AFTER all the front LEDS flash one time during "boot" and shortcut the chip for a few seconds. If you did this fast enough the powerled will turn to blinking green. If not, poweroff the router and try again.

The next step is to flash AN GOOD FLASH FILE. I've tried it 10 times with the original netgear flash file but that didn't work. Well the flash procedure worked, the TFTP reports it's PUT command correctly but the led didn't turn Orange flashing after the TFTP command.

But I managed the get it working with an DD-WRT mini flash file! I've upload the mini flash file with TFTP en voila! It's running smoothly!
Wait a minute or 5 and the router reboot to normal the normal state.
launch the routerwebsite and upgraded to the latest KONG DD-WRT.

So happy that it works!. And to be sure I have ordered an serialcable for 2 euro at ebay for the next time I brick my router. Short cutting  an chip is not ideal!

Gerbil
Gerbil's picture
Hello,

Hello,

I am using Linux and I needed to make some things in another way:
a) after erase linux and reboot, I needed to set up the IP manually on my Linux-System (192.168.1.2 / Mask 255.255.255.0)
b) the Linux tftp-command doesn't work in one step:
- tftp 192.168.1.1
- binary
- put WNR3500L.chk

Binary mode is important, because text mode transfers a corrupted firmware image. SOme tftp-clients may select binary content automatically, but my Linux standard client doesn't. (I tried ascii twice and got another byte count when using binary.)

After a while the system rebooted and I was able to configure the device again.

Maybe a erase nvram (or vice versa) may be useful before step A?!

Bye,
Tom

Joseph
Joseph's picture
Thank you, this is excellent.

Thank you, this is excellent. Screencaps are great too.

tissit
tissit's picture
Wait FIVE MINUTES for reboot?

Wait FIVE MINUTES for reboot? WTF?

MDA400
MDA400's picture
*kyle said: Hey hahaha funny

*kyle said: Hey hahaha funny question, i got the firmware back on there - when i hit the router @ 192.168.1.1 via web interface it prompts me for user name and password.... I have no idea what it is! admin/password doesn't work.... Can the router possibly have cached my old stuff from ddrt or even locked me out now? Now that it is back to the factory firmware... can i press the reset button on the back of the router?? please post!*

Im having this same problem too! Router works perfectly. routes both IP addresses and DNS servers correctly, but i cant configure the router because the admin and password dont work. I have to statically set my IP to a 192.168.1.x number because it gives me a 192.168.0.x number if i dont which means its got DMZ on.

eckertdarw
eckertdarw's picture
Ugg Boots OutletUggs SaleUgg
Vlad
Vlad's picture
I got this in the end with

I got this in the end with flashing power on my router. I can't do nothing any more. What should I do, please? Thanks
E:\Netgear 3500L>tftp -i 192.168.1.1 PUT WNR3500L-V1.2.2.44_35.0.53.chk
Timeout occurred
Connect request failed

Vlad
Vlad's picture
I got this in the end with

I got this in the end with flashing power on my router. what should I do? please...

E:\Netgear 3500L>tftp -i 192.168.1.1 PUT WNR3500L-V1.2.2.44_35.0.53.chk
Timeout occurred
Connect request failed

Brandon C
Brandon C's picture
Vlad,

Vlad,
Was that after you did an erase linux or what did you do to put the router in tftp receive mode?

Vlad
Vlad's picture
Sort It out! Many thanks. I

Sort It out! Many thanks. I had to setup a static IP for my laptop after I did erase LINUX and reboot the rooter. Having a static IP addres in that moment (192.168.1.5) I was able to use the TFTP with that comand. So your post was really a big help for me, because didn't know what to do any more. Regards.

Grigorij
Grigorij's picture
Thank You for the guide. It

Thank You for the guide. It did it.

I had to do 30/30/30 after TFTP.

Vyri
Vyri's picture
Followed the tutorial and it

Followed the tutorial and it worked great. I did have the problem with the user/pass in Telnet, but was fine after resetting and using root/admin. Also had to do a 30/30/30 reset after flashing the new firmware before default Netgear user/pass would let me in. Great guide. Cheers!

Vlad
Vlad's picture
Hello guys ! I tell you a

Hello guys ! I tell you a easy way, as well to reflash to factory firmware for Netgear wrn 3500l.

If you have dd-wrt installed then:

1 Update to Tomato firmware:

tomato-K26USB-1.28.7440MIPSR2-Toastman-Ext.trx Just google for this file. This is very nice but unfortunately don't get good WLAN speed.

2 Update to Netgear firmware

WNR3500L-V1.2.2.44_35.0.53.chk

And that is It. Nothing else.
The best WLAN speed for this router I get It with the Netgear firmware. And this is a big shame ..., just 3MB/sec = 24 Mbs - WLAN speed. With other firmware I get 1.8 - 2 MB. So where are the 300Mbs they are screaming up about?! Not even 145 Mbs you don't get ...I'm not happy at all with this router. Or maybe my router is defective - something wrong with the antenna.

Vyri
Vyri's picture
 

 

Vlad said: The best WLAN speed for this router I get It with the Netgear firmware. And this is a big shame ..., just 3MB/sec = 24 Mbs - WLAN speed. With other firmware I get 1.8 - 2 MB. So where are the 300Mbs they are screaming up about?! Not even 145 Mbs you don't get ...I'm not happy at all with this router. Or maybe my router is defective - something wrong with the antenna.

You are seeing the same as me.  I had serious issues just 25ft from the router with internet speed, not just network transfer rates, with almost no signal on DD-WRT firmware. As soon as I flashed back to latest stock I am now getting 20Mbps+ at the furthest extremeties of my house and 25Mbps right next to it which is what my ISP supplies. File transfers in network are same as you. I tried tweaking DD-WRT for over 2 months but nothing worked. My old WGR614v9 was out performing it by more than a 4-1 ratio in some cases. Think I'm headed for the N66U.

Vlad
Vlad's picture
Vyri said:

Vyri said:

Vlad said: The best WLAN speed for this router I get It with the Netgear firmware. And this is a big shame ..., just 3MB/sec = 24 Mbs - WLAN speed. With other firmware I get 1.8 - 2 MB. So where are the 300Mbs they are screaming up about?! Not even 145 Mbs you don't get ...I'm not happy at all with this router. Or maybe my router is defective - something wrong with the antenna.

You are seeing the same as me.  I had serious issues just 25ft from the router with internet speed, not just network transfer rates, with almost no signal on DD-WRT firmware. As soon as I flashed back to latest stock I am now getting 20Mbps+ at the furthest extremeties of my house and 25Mbps right next to it which is what my ISP supplies. File transfers in network are same as you. I tried tweaking DD-WRT for over 2 months but nothing worked. My old WGR614v9 was out performing it by more than a 4-1 ratio in some cases. Think I'm headed for the N66U.

Thanks for post ! Speaking with Netgear tech . support they said will replace my router, but after reading your post I'wont expect any major change. :)) I'll take a look to see what 's about this N66U - I need better WLAN speed.

David Hemmingsen
David Hemmingsen's picture
Thanks!

Thanks!
Followed the tutorial. Worked until the logging in to your router again part. Had to make a simple reset to login to the router again :)

Hogeye
Hogeye's picture
I followed Vlad's post and it

I followed Vlad's post and it worked great. I went from DD-WRT to Tomato to Netgear firmware with no problems at all. DD-WRT loaded the Tomato.trx file, and Tomato loaded the Netgear.chk file.

I did a 30/30/30 between each firmware upgrade just in case. I am back to stock firmware using the WNR3500L as an access point.

Gazeteler
Gazeteler's picture
thank you very much for

thank you very much for sharing

Gazeteler

Ucak Bileti
Ucak Bileti's picture
We expect more shares

We expect more shares

Ucak Bileti

Ucak Bileti
Ucak Bileti's picture
Yes, just so Ucak Bileti

Yes, just so

Ucak Bileti

Cyring
Cyring's picture
I don't catch the point : why

I don't catch the point : why are U going back to Netgear firmware ?
Did I missed something or what ?

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