SDG2000X firmware, un documented function

[xpsion]

Dear,

I know that you can set the display brightness of the SDG2042X / series function generator, by pressing a certain key combination and then turn the rotary when it shows the brightness value in a scale of 1 to 10
Unfortunately, I don't remember the key combination and sequence anymore.
It is something using alse the left arrow key or both left and rigth arrow keys and simutaniously a thrird key.
But which one and in which menu, there are a lot of options: too much.
As far as i can remember it has been on this forum 6 years ago but i can;t find it.
Current Siglent team has no knowhow about it, and also i don't get any response from 6 other forums in the world.

So, what i think is possible is to open the unit and check which pin is used of the ARM processort to drive the backlight with an PWM signal.
Then in the datasheet I could trace back the register address of this signal.

But is there somebody arrounc that can read the firmware, so we can lookup where this register is set. then we can find the used key combination from the firmware routines, I guess ze can dissamble it ? or....

Any idea on this ?

Alex