Belkin N300 Debrick notes

· by Raghu Rajagopalan · Read in about 2 min · (415 words) ·
router homelab

Belkin f7d7301 debrick story

USB UART - Serial recovery

  1. USB UART/JTAG board from Ali - CJMCU FT232H

  2. Default mode is USB UART

  3. Router pins

    1. 4 pin header. Arrow marks pin 1 (VCC)

    2. Pin 2 - TXD

    3. PIN 3 - RXD

    4. PIN 4 - GND

      Only need to connect pin 2, 3 and 4 to pins on FT232h board. TX & RX are interchanged (TX on router goes to RX on board)

  4. When bricked, serial console did not show any output on power on. See recovery mode below.

Was it necessary

Probably not - but I doubt I’d have got the router back to life without it. Immensely helpful since it shows what’s going on when you’re trying to use the CFE miniweb. Also, I doubt I’d have tried tftp put unless I could see what was going on the serial console.

Belkin - recovery mode/CFE notes

  1. Doing a 30-30-30 reset with the WPS button seemed to put some life into the router so that it came out of it’s funk and serial console printed boot messages.

  2. Once serial console was available, setting static IP on PC to 192.168.2.x and browsing to 192.168.2.1 shows CFE recovery page.

  3. Flashing from CFE web browser DID NOT WORK - just shows the browser waiting

  4. CFE command to boot from tftp site did not work either [tftp transfer errors out ]

  5. TFTP put from the PC worked consistently:

    1. tftp -i 192.168.2.1 put dd-wrt.v24-37305_NEWD-2_K2.6_mini_f7d7301.bin

      1. This is msys tftp. Any linux one will do also.

    2. Power on the router - it should pick up the tftp transfer and start flashing.. Sometimes takes a couple of tries.

Firmware notes

  1. dd-wrt is broken horribly - AVOID

    1. k26 - lan ports didn’t work.

    2. k30 - broke router.

    3. does not flash properly through CFE - the only one that did was the mini build above

    4. USB ext2 partitions not recognized.

  2. Tomato fw

    1. Shibby build 140 works well - pick one that clocks in under 8MB bin file

      • But printer discovery (multicast DNS) is broken on shibby 140

    2. FreshTomato-MIPS works well.

For future brick proofing

  1. backup CFE - dd if=/dev/mtd0 of=/tmp/cfe.bin

    1. link to cfe - Mega backup folder

  2. Restore - if you have a cfe console, then you could probably do flash

    • but if you need a cfe backup, then your cfe is likely borked and only a jtag restore is going to help.

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