I was playing with this DSO5102P, upgraded firmware, leave on about 20min, calibrated, and let's play
well, I think the images speak by themselves, the scope is clean, no near equipment making noise , earth on my office is good and tested.
question is, I think its firmware, I am trying to get more recent version, even on the huge thread, nothing..
probe was connected to square wave output of the scope
so, try harder to get firmware or send it to warranty, it still has 2 more years of warranty !