Why does my hp printer make noise (reset? recallibrate?) when I'm not using my computer?

I'll be sitting on the couch and it will just start making noise, not sure what it's doing but it happens several times a day.Why does my hp printer make noise (reset? recallibrate?) when I'm not using my computer?
Depending on printer type. The laser will periodically recharge the toner supply since it gets outdated from heat. A inkjet will perform maintenance to clean the heads. Suggest you turn the unit off if it will be more than a couple of hours before you plan to use it again.Why does my hp printer make noise (reset? recallibrate?) when I'm not using my computer?
I would think it has an internal clock that resest it's self. I have a MCF 210C that resets it's self every night at midnight. It even changes it's self for the time changes in Spring and Fall.

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