So a quick look in Ghidra revealed the passphrase: "hsa3g".
Yeah, for both. Then no surprise if it bricks after accidentally updating with the wrong file.
The update uses the same format to Hantek DSO2xxx series.
I modified the build scripts, with this you can extract and build update packages :)
It shouldn't be hard to figure out what to backup and create a restore package just like in the DSO2xxx.
The update file from the thread does this:
echo "update start"
rm -f /lib/firmware/*.bit
cp /tmp/dmm_client/DMMCore /dso/app/
cp /tmp/dmm_client/dm65fpga_16.bit /lib/firmware/
cp /tmp/dmm_client/dm65fpga_21.bit /lib/firmware/
cp /tmp/dmm_client/libscpi.so.2.1.0 /lib/
cp /tmp/dmm_client/*.bin /dso/app/res/icon/
Attaching the scripts and both decrypted firmwares packages.