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arthurwinslo

join:2012-11-30
Toronto, ON
reply to torobull123

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

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)



torobull123

join:2009-06-20

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.


mlord

join:2006-11-05
Nepean, ON
kudos:13
Reviews:
·Start Communicat..

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.


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.