How to re-flash the firmware in a Netgear WNDR4500v2 router when the normal admin page cannot be accessed.
Here is the process, it is slightly convoluted and you need to follow the steps carefully. I've only done this the once so I am by no means an expert.
1. Make up USB or RS232 to TTL adapter (3.3V).
2. Connect to PC serial program. Something like teraterm or PuTTY.
3. Connect TTL to J11 in router pin 1 = 3.3V, pin 2 = TX, pin 5 = RX, pin 6 = GND. Pin 1 is closest to the edge of the PCB.
4. Set the terminal app to 115k baud.
5. Power the router and debug info should appear. If not swap the RX & TX lines. Do not continue until you have established comms with the router.
6. Hold down CTRL+C in the terminal prog and re-power the router.
7. This should give a CFE: prompt.
8. Then use download and use tftp2.exe (from: [ Ссылка ]) to flash the .chk file (from [ Ссылка ]).
9. Disconnect from the normal WiFi network.
10. Connect one of the router's LAN ports to the PC ethernet port.
11. Go to network connections and right click on the LAN connection, right click properties, internet protocols, use following IP address: 192.168.1.10, subnet 255.255.255.0, default gateway 192.168.1.1, default DNS 192.168.1.1
12. Run the tftp2 program, server = 192.168.1.1 choose the file.
13. In the terminal program issue the following command: nvram erase
14. The power LED should now flash.
15. In tftp2 click upgrade.
16. In the terminal program issue the following command: flash -noheader : flash1.trx
17. The progress bar should move in tftp2.
18. If it doesn't reboot the router, re-power the router and if the power LED is flashing, click upgrade in tftp2 again.
It should automatically reboot and start working.
