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torobull123

join:2009-06-20
reply to arthurwinslo

Re: Bricked WRT54GL v1.1. Toronto repair shop?

said by arthurwinslo:

torobull, I know you said you couldn't ping the router but did you try hard setting your ip to the 192.168.1.10 ip address and see if you could ping your gateway?

Most of the bricks that I've experienced on broadcom based routers didn't harm the bootloader (which is all that needs to be working in order to tftp upload any of those DD-WRT/Tomato bins back to the modem)

Ya i tried static ip on my pc. Still couldn't ping.

I pretty certain that the bootloader is messed up and the ethernet flash won't work. Ive tried many times

arthurwinslo

join:2012-11-30
Toronto, ON
I see. At this point, you have nothing to lose by trying to JTAG it yourself then. It really isn't as scary of a task as it may seem, just take your time.

My GL had no solder in the JTAG header points so I was simply able to tilt a pin header enough to maintain contact to flash the router back in a minute. If you're going to go the serial method, then get some headers soldered to it and call it a day. It would just be a shame to lose a GL over what is really a small task to resolve.

moffa

join:2007-10-14
Ajax, ON
reply to torobull123
There is a way to unbrick it by shorting some pins. I've tried it on my old router. Let me see if I can find the guide. Of course it's not recommended and stresses your chip but if you were going to junk it, I don't see why not

arthurwinslo

join:2012-11-30
Toronto, ON
Yeah shorting the flash mainly pertains if you cannot write back to the flash via JTAG. It won't really help if the data on the flash is messed up in my experience. You'll still end up having to reflash anyway.

moffa

join:2007-10-14
Ajax, ON
reply to torobull123
This is the guide I used »blog.linoweb.com/?p=116

I also had to use pin 16/17 instead of 15/16

arthurwinslo

join:2012-11-30
Toronto, ON
+1

mlord

join:2006-11-05
Nepean, ON
kudos:13
Reviews:
·Start Communicat..
reply to arthurwinslo
The "pin-shorting" is a way to prevent the bootloader from reading/applying screwed-up data from the parameter block (aka "nvram"), as well as preventing it from loading a messed-up firmware image. The idea is that by shorting a couple of pins at the right instant, the wrong flash address gets accessed instead of the parameters, and the whole thing gets rejected by the bootloader due to bad checksum. So the bootloader can then boot successfully.

I've only ever needed to do that (and figured it out myself from scratch) when setting the wrong CPU clock frequency, preventing even JTAG access. But it could also be useful if other stuff is messed up.

But regardless, do NOT throw that WRT54GL away! It can be revived. So even if you get a new router, keep the old one. Go ahead, learn and try the JTAG method and/or any of the other ways discussed. What do you have to lose? Nothing! And the experience can be very handy in the future.


torobull123

join:2009-06-20

2 edits
said by mlord:

The "pin-shorting" is a way to prevent the bootloader from reading/applying screwed-up data from the parameter block (aka "nvram"), as well as preventing it from loading a messed-up firmware image. The idea is that by shorting a couple of pins at the right instant, the wrong flash address gets accessed instead of the parameters, and the whole thing gets rejected by the bootloader due to bad checksum. So the bootloader can then boot successfully.

I've only ever needed to do that (and figured it out myself from scratch) when setting the wrong CPU clock frequency, preventing even JTAG access. But it could also be useful if other stuff is messed up.

But regardless, do NOT throw that WRT54GL away! It can be revived. So even if you get a new router, keep the old one. Go ahead, learn and try the JTAG method and/or any of the other ways discussed. What do you have to lose? Nothing! And the experience can be very handy in the future.

Do you need a special pin to fix a router with a messed up bootloader (no ping response)? R2 firmware running on a R1 device. Or is the pin header in the ebay jtag package enough for any kind of brick fix for the wrt54gl?

»www.ebay.ca/itm/JTAG-Cable-Links···0wt_1397

What about solderless pogo pins?

»www.ebay.ca/itm/Pogo-Pin-Adapter···2wt_1163

mlord

join:2006-11-05
Nepean, ON
kudos:13
Reviews:
·Start Communicat..
That's the type of "JTAG" thing I used here -- it does REQUIRE that you have a PC with a real (non-USB) parallel port. Modern machines may not have one!

There's also a similar, more versatile device available cheaper from within Canada:
»www.ebay.ca/itm/Buffered-JTAG-de···89738333

A better device for less money, that, but more complex to use.

Both types of "JTAG" include all you need, including the header pins: but they do require soldering.

I don't know anything about POGO pins.


Teddy Boom
k kudos Received
Premium
join:2007-01-29
Toronto, ON
kudos:21
reply to torobull123
If you are just soldering pins into empty holes, it really isn't that hard.

pogo pins work great as long as you can hold them mechanically secure. We drilled pogo pins one at a time into a plywood board to create production test jigs at an ex-employer. Very reliable connections, and long lasting.

The solderless headers also work fine, if the holes for the JTAG location are empty (sometimes those holes are already filled with solder, which you would have to get out--not so easy for a complete novice). They aren't super fantastic though. Hole diameters are highly variable from one product to another. The WRT-54G v2 might have exactly the right hole diameter, but the WRT-54GL v1.1 might have holes that are too small.... With soldered joints, the solder makes up the difference for a "wide" range of hole sizes. For a solderless header to work it has to be pretty precise.

Anyway, I'm happy to flash WRT-54GL for the same $10 as cable modems. I don't have a ton of experience doing it, and there are some differences, so we'll have to have some time to work on it, just in case.
--
electronicsguru.ca


fixer

@teksavvy.com
I have unbricked a couple of wrt's by shorting the NVRAM to erase it. Its easy and requires a simple sewing needle and a magnifying glass. Then just reloading the stock firmware with a ttftp client.


torobull123

join:2009-06-20
reply to torobull123
Just bought and flashed my new Linksys e1200 v2 with tomato-E1200v2-NVRAM64K-1.28.RT-N5x-MIPSR2-104-Max.bin

Working great. Still considering buying the jtag to fix the bricked wrt54gl. Why not. wrt54gl is still an expensive router.

I going to try to do it solderless by taping the pins touching the side of the jtag port. I know thats a flaky way to do it, but I am scared of screwing up the router board with zero experienced soldering.

arthurwinslo

join:2012-11-30
Toronto, ON
reply to Teddy Boom
Teddy, the holes are the same size as the Motorola Surfboards D2 series. There is also a profile in your JTAG NT software for the GL as well.

All you'll need is a dump of someone elses GL or GS that are readily available on DD-WRT.com or alternatively, flash the bootloader, get a serial connection with your rs232, make up a new hardware mac id to recreate the nvram and then tftp over whatever broadcom compatible build necessary.


Teddy Boom
k kudos Received
Premium
join:2007-01-29
Toronto, ON
kudos:21
said by arthurwinslo:

Teddy, the holes are the same size as the Motorola Surfboards D2 series.

But the holes on the SB5100 and the SB5101 are actually slightly different

Thanks for the info though!
--
electronicsguru.ca

arthurwinslo

join:2012-11-30
Toronto, ON
Not enough for it to matter. You can take the same pin header and have it fit both modems as well as the router. Quit being a stickler.

mlord

join:2006-11-05
Nepean, ON
kudos:13
I tried a standard pin header in an unmodified WRT54GL v1.1 here today -- really difficult it keep it in contact without soldering -- loose fit. But no harm in trying, and with long enough header pins it might be doable.

arthurwinslo

join:2012-11-30
Toronto, ON
mlord totally, if you're using a parallel programmer then it will be more effort than it's worth. The programmer that Teddy and myself has can reprogram a GL in about 20 seconds so it takes no effort to hold the header enough to detect the flash and program it.

edit: buy yourself a couple double the length (i forget the pitch right now) pin headers and you'll be able to just press slightly on the header holes to maintain perfect contact.


torobull123

join:2009-06-20

1 edit
reply to torobull123

Re: (FIXED) Bricked WRT54GL v1.1. Toronto repair shop?

ITS FIXED!!!!!!

Just got the ebay jtag cable.

Erased nvram with TjTag v2
Regained pinging
Used TFTP to reflash via ethernet with Guspaz's "Tomato/MLPPP 1.27-mp3alpha7"
Reboot

And its WORKING!

Hurray! Did it all solderless. Although it is very flaky, when tilting the pin header to make a connection.

So glad that I could salvage this great & still pricey router.

mlord

join:2006-11-05
Nepean, ON
kudos:13
Fantastic news! Congratulations, and Well Done!

SonicSam

join:2006-05-27
Ottawa, ON
reply to torobull123
Congrats on fixing it, when I broke my WRT54GL I read online that if you short 2 pins, you can enable tftp and upload a replacement firmware.

I cannot believe it worked, but it did, I was going to suggest that to you. Might have saved you a bit of money, but the JTAG solution is much better.

Edit: Oops it seems someone already mentioned this with more details, my apologies!

jerrycan

join:2010-11-05
Waterloo, ON
reply to torobull123
redacted


torobull123

join:2009-06-20
reply to torobull123
I did a bad firmware flash on purpose today. Just for fun. Repeating results.

Fixed quickly again.

mlord

join:2006-11-05
Nepean, ON
kudos:13
Well, now that you have jtag, you could pull down the source code and build system for Tomato and customize the firmware to your liking!