HELP WRT150N v1.1 bricked - Tried JTAG, SERIAL, TFTP

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HELP WRT150N v1.1 bricked - Tried JTAG, SERIAL, TFTP

DonParlor

I recently found my router (WRT150N) being unresponsive. I couldn't access it via web browser, so I started to look for solutions to get it back on. I've read a lot! I started by trying a TFTP firmware upload but no luck. I then created a serial connection, I stopped router while booting with CTRL+C, erased nvram and kernel, uploaded firmware via TFTP, but not luck again, router was always asking for a firmware. Then I started to think it was a corrupted CFE.
I've received my JTAG last week, soldered pins to board, and hooked all wires following DIYGADGET procedure described here: http://www.tiaowiki.com/w/Debrick_Routers_Using_zJTAG_and_DIYGADGET.COM's_FTA_JTAG_Cable
I erased Nvram and kernel, and I could also erase corrupted CFE. I then installed an exact copy of the original CFE for my Linksys WRT150N v1.1 which I applied my own MAC address to the CFE prior to installing it. After the CFE had been installed, I rebooted and opened a serial console (Putty), stopped the booting process and uploaded the firmware via TFTP. I then reboot but... The problem remains! Even with a fresh CFE and Firmware, it keeps requesting for a firmware...
Is there something I am missing here? Is there a step I did wrong? Please, I need your help...
Vincent

mstombs

Very unlikely CFE corrupted - unless you interrupt a CFE re-write.
You should readback flash partitions before erasing, and after re-writing to see what, if any, changes are made.
Failure to boot, stuck at CFE prompt will either be corrupt nvram or firmware. If nvram erased the CFE should repopulate it with factory defaults.
You should be able to monitor boot process with serial console. a hardware fault, such as failing PSU brick (easily fixed) may lead to a boot-loop, with router crashing during boot process.
What do you mean 'router asking for firmware'? I don't know that specific router, but sometimes can be configured to load firmware from a remote tftp server. Also some versions of tftp/CFE have limit on size of firmware that can be loaded, their might be a minimal size dd-wrt firmware that will work not a full Linksys.

DonParlor

Thank you for your answer.
I understand your claim on CFE not being corrupted... Here is a better description of what I did from the beginning. At first, I couldn't access my router via web browser, so I started to look for solutions to get it back on. I've read a lot! I started by trying a TFTP firmware upload but no luck since router was always going back into TTL=100 which is a request for a firmware. I then created a serial connection, I stopped router while booting with CTRL+C, erased nvram and kernel, uploaded firmware via TFTP, but not luck again, router was always asking for a firmware. Then this is why I started to think it was a corrupted CFE.
I order a JTAG and received it last week, soldered pins to board, and hooked all wires following DIYGADGET procedure described here: http://www.tiaowiki.com/w/Debrick_Routers_Using_zJTAG_and_DIYGADGET.COM's_FTA_JTAG_Cable
I erased Nvram and kernel, and I could also erase CFE. I then installed an exact copy of the original CFE for my Linksys WRT150N v1.1 which I applied my own MAC address prior to installing it. After the CFE had been installed, I rebooted and opened a serial console (Putty), stopped the booting process and uploaded the firmware via TFTP. I then reboot but... The problem remains! Even with a fresh CFE and Firmware, it keeps requesting for a firmware...
With help from some people, we also supposed the PSU was faulty, but it shows a steady 12.24V. It looks OK. So I looked into the serial console script, and it mentioned the following right after the upload:
ERROR. Flash device write error at address 1c06b6d2
Failed.: I/O error
*** command status = -4
Then on reboot, it says:
Invalid boot block on disk
Then the conclusion we made was a bad flash chip...
I see what you suggest here, that I upload a DD-WRT firmware. I didn't try this yet, because I was trying to upload OEM firmware. This router has never been installed with another firmware than OEM. Maybe I should try this, but so far, it looks like a hardware failure for unknown reason. I'll try uploading a minimal size firmware (DD-WRT) and update you about this.
Thank you for your help mstombs,
Vincent

DonParlor

I tried uploading a dd-wrt firmware but CFE will not accept it. I tried different sizes dd-wrt firmwares but they were all rejected. Then it leads me to believe the bad flash chip is the conclusion. It would mean my router IS really dead.
If you have any other ideas, don't hesitate to share with me,
Thank you for your help,
Vincent

mstombs

Bad luck, does seem to be a hardware error in flash, probably just the last sectors that contain the nvram, but interesting you get as far as messages from the bootloader - it would be more likely to crash I would have thought. Some flash chips are a bit too clever can lock bad sectors till a higher level system can remap them - but CFE too dumb to make use of. Broadcom's technique of using the one flash sector for nvram is known to be fragile, the way flash works is that to change one bit a whole sector is erased and re-written. While the flash may have a wear life of 400,000 writes if something goes wrong and does an nvram commit every second it will be dead in a couple weeks.

[deleted]

I agree with mstombs. It seems to be a hardware error in flash. I am closing this topic.
If you need this topic re-opened feel free to contact me or admin by private message.