-Im a bit disappointed can't dim panel backlight. .it's too bright for me ! trace and grid dims but bl not? Why? is there a way to mod this? ( even opening/cutting/ soldering something )
You could use an 555 timer as an pwm; the circuit would be quite simple and small. Then you could control the backlight by a potentiometer; but you have to drill a hole for the pot
It would be cool, if the scope automatically dims the screen in dependence on the ambient light, like any mobile phones already does
For that you need some kind of photosensor which is mounted on the outside of the scope and a circuitry which convert the signal of the sensor to a PWM.
If you don't need the option for adjusting the brightness after modding, it's even simpler.
1st possibility: The LEDs are driven by a voltage source with current limmiting resitsor(s); change the reistor(s) to a higher value.
2nd possibility (more unlikely): the LEDs are driven by a current source; change the sense resistor which adjusts the current value to a bigger one.
Can i improve input noise shielding cables or chips?
Yes it could be possible, but for that you must know the source of the noise. If it would be easy I think Rigol did it already by themselves
If you think it'ss the wires, then you could check it by adding some noise on the wires (e.g. via a transformer) and watch if something changes.