CA, that can be a shitty switch.
turn them 15x and try again
the 535 looks fine, a happy scoope,
well done
Enjoy the dual time base, "intense by A" and so on.
535A can run also some very amazing plugins, by example:
Spectrumanalyzers up to 40GHz (requires seperate cable for sawtooth and RTFM) (1L5, 1L10, 1L20, 1L30, 1L40) ! rearswitch is to set for 150V)
Sampling 1GHz = 1S1 or N
Diff ! 10µV/cm comes from 1A7 or 1A7A
Diff with comparement voltage: 1A5
1 Channel, L, A, B
2 Channel, CA, 53/54C, 1A1, 1A2
4 Channel: M, 1A4
Plugins begin with a letter are made for 15MHz scopes,
Plugins with a 1 are made for faster scopes and work also in the 53x