wavetek 23xt slow voltage rising on dc range

[ivi_yak]

Hi,
I have a problem with Wavetek 23xt,
when I measure voltage on DC range its start slowly rising to voltage in circuit also when I short probes its start slowly discharge to zero from voltage I have get.
Could anyone have the same one bug what it could be?

[dacman]

Clean the function switch contacts and use a contact lubricant.

[ivi_yak]

Do you mean function selector wheel? thx for reply

[dacman]

Yes.  Clean the contacts that are controlled by the knob used to select the different functions and ranges.

[jackthomson43]

You should clean your electronic devices regularly. I think you should open it up and do a little dusting. https://www.theengineeringprojects.com/2019/09/schottky-diode-schottky-barrier-working-application-characteristics.html

[ivi_yak]

Fixed!
I found two sprinned balls which maintain switch-wheel have lost their positions and the contact pressure was not enough to hold functionality.
Reinstall them with vaseline and back to life 

thanks all for reply