1) Set your computer's ip manually to: 192.168.0.X (not 1) AND set your subnet mask to 255.255.255.0.
2) Unplug the power cable to the router
3) Press the reset button and plug in the power cable when the power led flashes orange release the reset. go to 192.168.0.1
4) Upload your original firmware and wait

например, DIR615E4_FW513B02.

То есть последняя.

DIR615E4_FW511RUB03beta02 - эту тоже пытался записывать. один черт..

а вот вашу - нет. попорбую конечно но что-то мне кажется шансы не велики.

The firmware update system doesn't support the HTTP header Expect: 100-continue, which is used in POST requests by most modern browsers. If the browser sends this header, it will wait for the server to send a provisional response with status 100 Continue before sending the file contents. This feature was added in HTTP/1.1 to allow servers to reject uploads without needing to upload the file first. The router's built-in HTTP server claims to support HTTP/1.1, but it never sends the 100 Continue response so the browser waits forever or eventually times out.

Internet Explorer 6,7,8 on Windows is known to work, as well as Firefox 13.0.1 on GNU/Linux, but problems have been reported with newer versions and most other browsers on GNU/Linux. Older versions of Firefox (4.x and below) are known to have problems, several people have been more successful with newer versions. Alternatively, you can use the curl command-line HTTP client like so:

curl -0vF files=@openwrt-ar71xx-dir-615-c1-squashfs-factory.bin http://192.168.0.1/cgi/index
There seems to be some compatibility issues with the firmware update system network stack and at least a Linux 3.5.3 kernel and curl 7.27.0. Even forcing curl down to HTTP/1.0 resulted in a hang. One known working configuration is NetBSD 5.1.2 with curl 7.26.0. *A use of Firefox 13 portable edition (on windows 7) was verified as successful. Also known that local IP should be 192.168.0.10. Then FF 13 portable also should work.