Netgear WNDR3400 v1

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Dark_Shadow

Need Help
After making connections and running probonly

E:\jtag>zjtag -probeonly
        ==============================================
               zJTAG EJTAG Debrick Utility v1.1
        ==============================================
 Set I/O speed to 30000 KHz
USB TAP device has been initialized. Please confirm VREF signal connected!
Press any key to continue... ONCE target board is powered on!
Probing bus ... Done
Detected IR chain Length is 1
CPU Chip ID: 10001100010000111101100011101100 (8C43D8EC)
    CPU Manufacturer :Unknown(id=8EC)
    CPU Device ID :C43D
    CPU Revision  :8
*** Detected a CPU but not in build-in list ***
*** You can set /skipdetect let operate continue ***
E:\jtag>

Dark_Shadow

Sorry, now with clock modifier

E:\jtag>zJTAG -probeonly /L1:3
        ==============================================
               zJTAG EJTAG Debrick Utility v1.1
        ==============================================
 Set I/O speed to 7500 KHz
USB TAP device has been initialized. Please confirm VREF signal connected!
Press any key to continue... ONCE target board is powered on!
Probing bus ... Done
Detected IR chain Length is 0
CPU Chip ID: 00000000000000000000000000000000 (00000000)
*** Unknown or NO CPU Chip ID Detected ***
*** Possible Causes:
    1) Router/Modem is not Connected.
    2) Router/Modem is not Powered On.
    3) Improper JTAG Cable.
    4) Unrecognized CPU Chip ID.
E:\jtag>zJTAG -probeonly /L1:3

[deleted]

Could you please try with /instrlen:32 and also clock modifier?
Thanks!

Dark_Shadow

Just an FYI, this one is bricked.

E:\jtag>zJTAG -probeonly /L1:3 /instrlen:32
        ==============================================
               zJTAG EJTAG Debrick Utility v1.1
        ==============================================
 Set I/O speed to 7500 KHz
USB TAP device has been initialized. Please confirm VREF signal connected!
Press any key to continue... ONCE target board is powered on!
Probing bus ... Done
Detected IR chain Length is 0
Instruction Length set to 32
CPU Chip ID: 00000000000000000000000000000000 (00000000)
*** Unknown or NO CPU Chip ID Detected ***
*** Possible Causes:
    1) Router/Modem is not Connected.
    2) Router/Modem is not Powered On.
    3) Improper JTAG Cable.
    4) Unrecognized CPU Chip ID.
E:\jtag>

[deleted]

Did you try TJTAG with Parallel port cable? If yes, what was the result?

Dark_Shadow

Yes same as above but tjtag dev seems to have stalled. Maybe personal maters in tornados life.

[deleted]

Are you sure hardware is not damaged and processor is operational ? Did you check VCC on board?

Dark_Shadow

Yes. It was working fine till I flashed the wrong build and over wrote the board data.

[deleted]

Bummer... 1st thing I would check is for Vcc at the serial header. If you have Vcc, then hook up a serial console connection. If not and the Power Supply is good, it's probably fubar.
If LEDs don't even flash when power plugged in and Power Supply is good then you may want to check fuse. Not sure what that unit has.. Some have a self resetting fuse.. Looks like a square, flat capacitor by the power connection. It is not surface mount. Others have a surface mount fuse.. Not sure if the surface mount fuse resets.

Dark_Shadow

No problems with power, no problems with LED. Got VCC. Got Serial output till wrong build was flashed. I need to flash the CFE and boarddata back on. Is this proc supported or can you add support?

Dark_Shadow

http://www.techinfodepot.info/wiki/Netgear_WNDR3400_v1.0

[deleted]

If you can't get any serial output, I think you will need to unsolder flash chip, program it and then re-solder.
Without proper CHIP ID detected, I think JTAG won't work. Did you try timing trick?
Did you try linking TRST <-> VCC with 100 ohm resistor link in a cable? Some processors does need an extra connection for jtag tools to work: Pin 1 TRST must be pulled high.
I presume you tried steps written on DD-WRT: http://www.dd-wrt.com/phpBB2/viewtopic.php?p=696256

Dark_Shadow

volkan-k wrote:Without proper CHIP ID detected, I think JTAG won't work

You are quite right. Can you not add support for it?
It was detected in the first post with no modifier

Dark_Shadow

Just measured, 3.25VDC at pin1 seial and pin1 JTAG.

[deleted]

you are using J14 and not J10 right?

Dark_Shadow

yes, it's even posted on my wiki

[deleted]

8C43D8EC is invalid CHIP ID. Probably not even coming from processor, but misinterpretation due to very high clock.
Please note that it should show proper CHIP ID in JTAG tools even if the processor is not supported. CHIP ID detection does not require processor support and invalid or no CHIP ID probably means no JTAG communication with the processor.

[deleted]

Could you please try linking between VCC and TRST with a 100 ohm resistor link in a cable.? And let me know the result.

Dark_Shadow

I don't have a 100ohm resister, can i just put the JTAG pin1 on the vcc of the serial console?

[deleted]

Yes, you can but only at your own risk. I did it on one of my routers without resistor and it just worked OK. Doesn't mean it will work for you.
It's said that Shorting can easily blow the output gates on CPU or FLASH which creates a true brick! You have been warned!

Dark_Shadow wrote: I don't have a 100ohm resister, can i just put the JTAG pin1 on the vcc of the serial console?