Thanks for your kindness, but I am only care about Rigol DG811 & related issues now.
It was -- you
"I think U r siglent Fans...."
With 02.05 first you need do is take cal and memory copy, just for cases something goes really bad. If you do not afraid this can jump over.
There is available method for this backup copy...
https://www.eevblog.com/forum/testgear/new-rigol-16-bit-function-generators-dg800900-series/msg3272174/#msg3272174Just including .GEL file to USB root and insert USB to running DG and when it ask you want FW update then yes (aftere then it run this small script). It write this data to this USB flash. So you need many USB or take them out and save.
Note, NAND backup takes long time and after it is ready rolling image stops rolling but it do not finish... I wait 5 minutes after rolling image stop and after then I shot DG off and take USB and read... all was there. I think it can also just pull out without power off.
This backup calib is much faster and after some time it stops and goes out. But if you do not take USB out then after some time it ask again do you want update... just cancel this.
after this or if you have jumped over this backup...
next step is downgrade it to official 02.02 FW.
Previously in this thread you can find link for download this official FW2.02 (it is one @tv84 message what is this link and nothing more.)
https://www.eevblog.com/forum/testgear/new-rigol-16-bit-function-generators-dg800900-series/msg3035640/#msg3035640This downgrade need do so that you insert this USB and after then power on with repeatedly pushing "Help/Local" button.
It do not work if DG us running and you insert this USB. Soon it ask do you want update and if you answer Yes it start... but it do not help at all.
It need do with this boot up method.
After your DG811 is normal DG811 but FW 02.02 then you can continue with much more critical things... following this
https://www.eevblog.com/forum/testgear/new-rigol-16-bit-function-generators-dg800900-series/msg3157600/#msg3157600note. After position 3 is finished. Your original Serial is still not shown in DG system info screen because it looks like it read it only when booting. Shut off and boot. Now it read serial and display it if all have gone ok.
Btw, I am not sure but previously I read from some Rigol official info that overall FW update USB flash need be 8Gb or less and also then here I have seen it need be least over 1G.
Always it need be in genuine native FAT32 and I think 4k cluster size.
For "magig" USB stic needed later I recommend Full format instead of quick format to FAT32, 4k cluster. I did it with windows 7 64 and no any single problem. Of course other things can work but I have done with these.
All these instructions here lack some small information and then you need bit guess what to do when you see things in real world happen. Of course this is because who write help instructions he know things but can not fully think what some other people do not know. Full perfect comprehensive manual for this hard work so it need read and read some comments here and collect all needed info BEFORE start doing and then do after all needed is ready.
Also after you have done downgrade to 2.02 succesfully test that you have tools for give SCPI commands. Example using Rigol UltraSigma.