is there any way to erase NVRAM?


G

gazel

Network Guru
Member
I updated my WRT54G with tomato 1.06 and then by accident set an invalid value to nvram. After that i cannot connect to it via web interface any more (i cannot even ping 192.168.1.1 successfully). I guess to erase all NVRAM information will fix it, right? Is there any way to do it?

Thanks in advance.
 
You just need to reset it, hold down the reset button for about 30 seconds, it should the reboot itself and come back up with all defaults.
 
ifican said:
You just need to reset it, hold down the reset button for about 30 seconds, it should the reboot itself and come back up with all defaults.
Click to expand...

Thank you but I'm afraid it didn't work - I tried that serveral times without any progress. BTW, what I did for the nvram is like:

nvram set sdram_init=0x008
nvram set sdram_ncdl=0x000
nvram commit

I want to find additional 16M ram in my system while for some mysterious reason it failed :(.

Is there any failsafe mode in tomato for this kind of situation? I don't have a jtag
 
unplug the router, push the reset button, and plug it in. after about 30 seconds it should reset... you may need to set the your IP manually and plug in... if you can ping, but can't use the web interface you can tftp the code.bin file to your router from a dos prompt

if all this doesn't work there is a pin you can short to the antenna ground. search for debricking
 
unplug the router, push the reset button, and plug it in. after about 30 seconds it should reset... you may need to set the your IP manually and plug in... if you can ping, but can't use the web interface you can tftp the code.bin file to your router from a dos prompt

if all this doesn't work there is a pin you can short to the antenna ground. search for debricking
 
digitalgeek said:
unplug the router, push the reset button, and plug it in. after about 30 seconds it should reset... you may need to set the your IP manually and plug in... if you can ping, but can't use the web interface you can tftp the code.bin file to your router from a dos prompt

if all this doesn't work there is a pin you can short to the antenna ground. search for debricking
Click to expand...

Thank you. I will have a try.
And yes, I found the WRT54G Revival Guide by Toxic, seems promising. :grin:
 
gazel said:
nvram set sdram_init=0x008
nvram set sdram_ncdl=0x000
nvram commit

I want to find additional 16M ram in my system while for some mysterious reason it failed :(.
Click to expand...

That's a dangerous game to play...

JTAG or pin shorting is the only way to go. Pin shorting is a dangerous game as well - be absolutely sure you're shorting the correct pins otherwise you could fry your flash chip permanently (I speak from experience unfortunately :) )
 
I tried the pin16 shorting and successfully pinged. then i successfully uploaded a official firmware and waited for enough time - only power and the correspoding ethernet flicker during this period. Unfortunately I cannot either enter the web interface nor telnet to router. Any ideas?
 
the linksys firmware does not support telnet (at least it didn't when I used it)

if you can ping the router, you can try tftp the tomato code.bin file.

(have you tried a 30 second reset with the linksys firmware?)
 
gazel said:
I tried the pin16 shorting and successfully pinged. then i successfully uploaded a official firmware and waited for enough time - only power and the correspoding ethernet flicker during this period. Unfortunately I cannot either enter the web interface nor telnet to router. Any ideas?
Click to expand...

You're over the worst part. Now you just need to get a firmware onto the router using tftp. It's not hard, but you may need to try a few times to get the timing right.

Basically, you need to have the tftp command ready to go, reboot the router, and while it's booting keep trying the command until it works. If it doesn't upload successfully, reboot and try again...

The Windows tftp command should look something like this:

Code: 
tftp -i 192.168.1.1 PUT code.bin

where "code.bin" is the name of the firmware image.
 
After I tried to upload a tomato firmwire instead of the official one, finally it worked! Thank you all you guys!

BTW, agree with tievolu, it's really a dangerous game: one time when i shorting pin16, I saw sparkles! I'm just lucky enough not to fry my flash.
 
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