Keysight 3000T DC offset problem

[apblog]

All of the channels on my Keysight MSOX 3104T have a displayed DC offset of about -0.25 mV, in 1:1 mode with no probe connected.  That's -2.5mV with an x10 probe.  This holds true for both DC and AC coupling.

I've had this scope for about 3 years, and it was a keysight "premium used" refurb.

I only noticed this because I was trying to look for dc offsets in a passive RF detection circuit.

I was wondering if other 3000T owners have this same problem.  I might be expecting too much accuracy...

EDIT:

they list the dc vertical offset accuracy as "± 0.1 div ± 2 mV ± 1% of offset setting", so I guess I'm doing OK with this scope.

Still annoying though that it can't be tweaked out by the user.  On an analog scope, you just adjust the vertical offset knob.  But on a digital scope, adjusting the vertical offset knob changes the trace position, but of course all off the various read out numbers are still wrong.

[mikeselectricstuff]

Have you tried a self-cal ?

[apblog]

Have you tried a self-cal ?

I haven't.  I don't have the appropriate cables, and I'm a little afraid of messing it up.  I need this scope for work, I can't risk any down time right now.

Mostly I just want to if this is similar to what other people with the same scope are seeing.

[Bud]

DC offsets are typically taken care of by user self calibration.