tekky I have a bricked E2000 from installing the wrong firmware on it. Do you know where I can get some good instructions on how to unbrick it using that nokia cable?
The dd-wrt forums are all over the place with no clear and concise step by step guide. Cheers!
Before reading the rest of this post, are all the lights of the ports on the router solid colors when immediately powered or is only the power LED flashing?
If it's the first, then your router is totally bricked, and I'm not quite sure if you can solve it from here. If that were an ASUS router for the same scenario, you can still unbrick it.
If only the power LED is flashing, then read on and be sure to read everything before starting.
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I've only JTAGed once on an Atheros based router. My setup was a breadboard, a MAXIM IC sample (MAX323) to convert 5V to 3.3V (free chips can be ordered on the website), an old PATA (IDE) ribbon cable, wires, and a serial port. Soldered the PATA cable to the JTAG pinouts on the router's PCB. Connected the rest on the breadboard with serial port wire leads.
That said, I'll try my best to make a guide that's easy to understand.
I believe the setup is similar for all routers. The Nokia way you described is a hack to eliminate using the IC and a serial port, supposedly making the recovery setup less complicated.
Also, the Nokia way uses a specific serial pinout to the side of the router, not the middle desoldered JTAG port.
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Tools required:
1. Solder + Soldering iron.
2. Wire cutters/strippers.
3. Screwdriver with appropriate Phillips heads
4. Multimeter
5. Nokia DKU-5 cable (Serial to USB, preferably official OEM version)*
6. A computer running Windows (although equivalent commands/programs can be used for Mac/Linux) and a free USB port
7. Tape (or sticky labels) + pen
*I've seen some guides that use the Nokia CA-42 cable, but I read new variants of this cable only have three wires and would need an external power source to drive 3.3V (e.g. two new AA/AAA batteries). I'm a bit confused since the DD-WRT serial recovery wiki (which is rarely updated) says you can use CA-42 cables.
Source:
http://buffalo.nas-central.org/index.php/Use_a_Nokia_Serial_Cable_on_an_ARM9_Linkstation
http://www.dd-wrt.com/wiki/index.php/Serial_Recovery
OpenWRT guide on info about serial cables:
http://wiki.openwrt.org/doc/hardware/port.serial
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Time required: 1-3 hours
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[ ] Stage One: Test the Nokia cable to see if the computer can detect the TTL serial connection.
1. Plug the Nokia cable into an open USB port of the computer.
2. Install drivers as necessary to detect COM ports. This is necessary so that when the connections are made, the computer can talk to the router.
If the cable does not show up on the computer, purchase a working cable or try a different computer.
3. Determine the COM port used on the computer for Serial. On Windows, you can easily tell from Device Manager under "Ports."
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[ ] Stage Two: Cut and identify pins on the Nokia cable
1. Using your wire cutters, cut the proprietary Nokia pin port connector from about 1-2 inches away. Separate and strip the wires on both ends. Be sure to leave enough space to still identify the corresponding colors.
2. Because of the small possibility that a cable can use different wire colors, we need to test which color lead corresponds with which.
If you refer to this page:
http://buffalo.nas-central.org/index.php/Use_a_Nokia_Serial_Cable_on_an_ARM9_Linkstation and used an OEM cable, then perhaps the wiring colors are the same.
You can read more about it in the serial recovery wiki:
http://www.dd-wrt.com/wiki/index.php/Serial_Recovery
The next step will guide you which pins you are interested.
3. Using a multimeter, use the test probe (beep) function to see which colored wire leads up to where.
You're interested in:
Pin 4 : 3.3 V (RED on DKU-5)
Pin 6 : RX (GREEN on DKU-5)
Pin 7 : TX (WHITE on DKU-5)
Pin 8 : GROUND (BLACK on DKU-5)
I don't have this cable, so you're going to have test yourself if those colors are right. If not, mark them appropriately using small pieces of tape (or sticky labels) and a pen.
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[ ] Stage Three: Open the router and solder pins.
1. Ground yourself. Touch a door knob or the casing of an unpowered power supply unit before handling electronics. Wear an Anti-ESD strap if you have one.
2. Unplug power and disassemble the E2000 router. Remove antenna wires and necessary screws using the screw driver and take the PCB board out of the housing.
3. Reverse the PCB over to reveal the JTAG port and side serial debugging port.
4. Solder: Nokia Cable | Router Serial
Pin 4 (RED) | Pin 1 (3.3 Volts)
Pin 6 (GRN) (RX) | Pin 2 (TX)
Pin 7 (WHI) (TX) | Pin 3 (RX)
Pin 8 (BLK) | Pin 5 (GROUND)
Note RX pairs with TX and vice versa. These connections are how the device receives and transmits info to another device.
5. Test the solder connections using a multimeter probe.
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[ ] Stage Four: Booting into the router via serial and flash back to stock firmware
Original Linksys E2000 firmware:
http://homesupport.cisco.com/en-us/wireless/linksys/E2000
Will finish later.
I used hyperterminal in Windows XP, but I believe you can also do this with PUTTY. I'm sure you can do that the same for Linux and Mac in Terminal.
The basics are to plug the router in and run a terminal console configured to listen to the serial COM port. Quit the boot-up command using CTRL+C. Then you can send an image (which will take about 40-45 minutes to do) via serial and reboot.
If something's not working, then check your solder connections.
**********Made some corrections on the Pin-outs. Please check again if you printed out the one earlier.**********
