JTAG and the WHR-G54S w/ pictures

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redhawk0
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PostPosted: Wed Jun 11, 2008 23:21    Post subject: JTAG and the WHR-G54S w/ pictures Reply with quote
Hi guys,

For all of you wondering about how to JTAG a Buffalo WHR-G54S unit. I know anectine17 covered it pretty extensively....and his ground-breaking work is VERY much appreciated.

So...I finally got around to working on one of these units that was bricked. I installed the JTAG header on the unit from the top of the board...but anectine17 was savy enough to figure out that this orientation is upside-down on the board....if the header was installed on the bottom of the motherboard then the JTAG cable could be plugged right on.

so...here was my solution....install the header on the top of the motherboard (normal configuration) but install the JTAG cable on backwards on only one row (data pin side) and bring a ground wire over to the ground pin of the JTAG cable.

I was able to -erase:nvram and -erase:kernel and recover this router. The next step was to do a -backup:cfe...this was also successful (doing it 3 times and comparing files for validation)

The unit would then take a tftp of the dd-wrt firmware...and is running great.

hope this helps someone else

redhawk



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Last edited by redhawk0 on Thu Jun 12, 2008 15:26; edited 1 time in total
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jmh9072
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PostPosted: Thu Jun 12, 2008 5:16    Post subject: Reply with quote
Ah. That's good to know. You are a clever one, redhawk!
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loco
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PostPosted: Tue Dec 09, 2008 0:41    Post subject: Reply with quote
that ground wire. where is it going to? appears to be shorting the ground to one of the data pins but from the pictures I can't tell which pin it's soldiered to under the jtag. thanks
redhawk0
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PostPosted: Tue Dec 09, 2008 0:44    Post subject: Reply with quote
loco wrote:
that ground wire. where is it going to? appears to be shorting the ground to one of the data pins but from the pictures I can't tell which pin it's soldiered to under the jtag. thanks


Its going to pin 6 on the JTAG cable connector.

It is the only ground and only one is needed.

redhawk

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Donny
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PostPosted: Tue Dec 09, 2008 4:42    Post subject: Re: JTAG and the WHR-G54S w/ pictures Reply with quote
redhawk0 wrote:

So...I finally got around to working on one of these units that was bricked.


Does this mean that the deer are now safe, but we have to now watch the advice that we haphazardly hand out? You're back?

I take it that if this was the only unit that one was going to jtag, this proves they could make a custom jtag specifically for this unit? Nice work.

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Eyedoctor2
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PostPosted: Thu Jul 30, 2009 16:32    Post subject: WHR-G54S Jtag question Reply with quote
Unfortunately, I did something stupid and bought first and asked questions (looked at this post) later.

I am attaching a schematic of the JTAG that I purchased on ebay. I wrote the seller but he didn't know how to use it with the WHR-G54s only the Linksys model. It was advertised on the ebay listing, however.

Can I use this JTAG with th G54s? If so how do I plug it into the board?

I already have the router opened and the debricking software ready to run.

Thanks in advance!



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redhawk0
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PostPosted: Thu Jul 30, 2009 16:33    Post subject: Reply with quote
yes...you can use it...just turn it around and add a ground as my picture indicates above.

redhawk

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Eyedoctor2
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PostPosted: Thu Jul 30, 2009 16:43    Post subject: Reply with quote
Redhawk: Thanks for the quick reply. I was hoping you would read the post!

By turn it around do you mean that I have to plug in into the underside of the board? Do I plug the red end into the square hole (#1)?

The reason I bought the cable is that I know nothing about doing this sort of thing but wanted to save my router. How do I make the ground wire?

Thanks for helping this newbie who is in over his head!!
redhawk0
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PostPosted: Thu Jul 30, 2009 17:06    Post subject: Reply with quote
no..turn it around only one row of pins...pin 1 of the connector plugs onto pin 11 of the header on the mobo.

don't forget to add a wire for your ground.

See the picture above.


If you really want to connect the header to the bottom of the board...go ahead...but you won't be able to put the board back in the case when you are done without modifying the router's case....my solution above requires no modifications...and you can leave the header soldered to the board.


redhawk

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Eyedoctor2
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PostPosted: Thu Jul 30, 2009 18:18    Post subject: Reply with quote
Worked like a charm!

Ran the HairyDairy software to erase the nvram and it gave me a operation completed successfully message.

But when I plugged in the router it still has 3 of 4 lan lights and the wan light on and can't be pinged.

What should I try next?

Thanks!
redhawk0
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PostPosted: Thu Jul 30, 2009 18:21    Post subject: Reply with quote
Erase both nvram and kernel. (do NOT erase wholeflash or CFE)

once you erase the nvram and kernel...then tftp the firmware to it again.

follow the peacock thread step #11 for tftp flashing.

Oh...BTW...the IP address for a buffalo is 192.168.11.1 not 1.1 ...it will be 192.168.1.1 only after dd-wrt is installed.

so for the static IP setup for tftp you would make your pc static set to 192.168.11.10 and 255.255.255.0....then flash it to 192.168.11.1 in the tftp utility.

redhawk

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DHC_DarkShadow
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PostPosted: Thu Jul 30, 2009 19:59    Post subject: Reply with quote
This seems like good Wiki material.
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redhawk0
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PostPosted: Thu Jul 30, 2009 20:11    Post subject: Reply with quote
Funny...I thought I put it in the wiki...I must have thought wrong....I'll try to get it added shortly....

BTW...thanx for helping clean up the corerev wiki page.....appreciated.

redhawk

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DHC_DarkShadow
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PostPosted: Thu Jul 30, 2009 20:18    Post subject: Reply with quote
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redhawk0
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PostPosted: Thu Jul 30, 2009 20:45    Post subject: Reply with quote
Added to "Recovering from a bad flash" page....subsectioned with the WHR-G54S JTAG info.

http://www.dd-wrt.com/wiki/index.php/Recover_from_a_Bad_Flash

redhawk

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Last edited by redhawk0 on Thu Sep 10, 2009 2:13; edited 1 time in total
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