Hi,

i think i bricked my ARV752DPW22. The bootloader isn't running anymore and i get following message:

ROM VER: 1.0.3
CFG 04
Read EEPROMX
 X
UART

I put the router into UART mode an tried to flash the u-boot.asc and a backup of the original firmware by using cat:

cat ARV752DPW22_orig.dump > /dev/ttyUSB0

After the upload is complete the serial console doesn't show anything. Any ideas?

Thanks, horst

Hi Horst,

check this thread. Maybe your serial interface is not set up correctly? cat would not know. Try minicom with ascii transfer set to 'ascii-xfr -nsv'. This should give you maximum control of what and how you send.

Have you tried the u-boot.asc from Attitude Adjustment rc1?
I did not yet have to debrick my ARV752DPW22, but the nor and brn Images of AA rc1 work well for me.

For my ARV752DPW I used this image. It should work on the ARV752DPW22, too. Both boards are pretty close. They use different switches - so the network is not going to work and you will have to use ubootwrite.py.

Use the U-Boot for ARV7518PW (they have the same switch configuration) from http://downloads.openwrt.org/snapshots/ … u-boot.asc and then use tftp to upload a working image. The U-Boot images from AA do not have a working network.

(Last edited by snk on 17 Oct 2013, 08:26)

I just did this procedure and "ascii-xfr -nsv" gave the right result. In particular I had a console ("screen /dev/ttyUSB0 115200
") open when the router was powered off and once it booted and gave me "UART" I did not close the screen session but from a parallel terminal did

ascii-xfr -nsv u-boot/recovery/openwrt-lantiq-arv7518pw_ram-u-boot.asc >/dev/ttyUSB0

and waited for it to finish. As soon as it finishes the serial console showed that the router started executing the u-boot. The thing I learned was that there was NO RESET to be done at that point. If I reset the router everything was lost and I had to start again.

At that point I disconnected the two things (3.3V and the short) that enabled UART because I read somewhere that this could cause problems

I took my backupped image and did the commands desribed in

https://forum.openwrt.org/viewtopic.php … 56#p214956

but I actually flashed the whole backup image because just to be sure (so it was  0x800000 long and started at 0xb0000000). Actually after the tftp transfer and before the copy I did a checksum:

crc32 0x81000000 0x800000

and compared it to the crc32 on my pc just to be sure that everything went fine.

At that point I reset the router and was as good (and as bad) as new.

(Last edited by guraltsev on 2 Mar 2014, 00:53)