Guys false alarm for replacement DMMs
, looks like factory did not bother to change SN sticker,
Found at home Analog Discovery 2 (I already forgot that I have it, because project was killed for which I got it, need to dig deeper maybe I will find something else at home
) All waveforms up to max 10MHz does not affect the readings, looked at the box of the DMM, sticker said something along the lines for internal use, so I won't bother getting 20MHz ARB from friends to test further.
Again sorry for false alarm, and thumbs up for Keysight!
Edit: PS. maybe someone found a soft case for U1280A? it does not fit in U1174A case and looks like Keysight does not have new soft cases. maybe it fits into Frankies' BM869s case?