D-Link DWR-921 C3 fault after install openwrt

Installing and Using OpenWrt
1

Hi, I flashed the D-Link DWR-921 C3 (Rev)
https://openwrt.org/toh/d-link/dwr-921#tab__revisions_c1c32
via openwrt-19.07.2-ramips-mt7620-dlink_dwr-921-c3-initramfs-kernel.bin router after a reboot, it went into recovery mode through the browser. An attempt to restore the original firmware or any other openwrt resulted in an error.

I connected via serial usb-to-rs232 directly through the board and saw the error log.
dlink_drw921c1_console

.
p chksum error ff00
P Section not found!
IP=192.168.123.254 NA=00:50:18:00:0F:FE
?
error command : '?'
# help
command list...
reboot
info
load
go
dm
wm
rm
copy
ip [ip]
mac [mac]
ping
areacode

# info
MODEL_NAME: CTG561DL_0T3
ROMID: @m!tr&d
ECN_NO: 20081226001
FMID: 6E24
PV: 1
IP: 192.168.123.254
BEID: 00:50:18:00:0F:FE
PSEC: FFFFFFF0 FFFFFFF0
#

Can anyone come across this?

2

what error ?

3

Did you try factory.bin image for recovery?
Did you try tftp client instead of browser? (Some version of jboot bootloader support both tftp and http recovery protocol)

4

Yes i try all get same
"ERROR"
I also tried the curl way but the response was the same.

5

I think what you want to use is a USB to UART.

Screenshot 2022-02-15 at 17-22-22 Amazon com HiLetgo CP2102 USB 2 0 to TTL Module Serial Converter Adapter Module USB to TT...
Screenshot 2022-02-15 at 17-22-22 Amazon com HiLetgo CP2102 USB 2 0 to TTL Module Serial Converter Adapter Module USB to TT...1578×691 96.3 KB

6

I used Ft232bl USB 2,0 to TTL converter and Putty to connect router and get this

.
p chksum error ff00
P Section not found!
IP=192.168.123.254 NA=00:50:18:00:0F:FE