It could have failed. ONLY those with an electronics background should read any further or those that hold all blameless for their injury or death.
6 years without a trip to a service center is amazing. I'm amazed you would suddenly shy away from such a printer.
I have an older laser printer, an HP Laser Jet 4000 (bought in 1999 or 2000?) It works well, except...it imparts quite a bit of static to the printed page. As a result, it has become impossible to duplex print more than one page at a time. Previously, it would duplex 50 pages at a go.
I do live in New Mexico, a dry climate, with about 23-25% humidity. However, this problem did not occur during the first six years of use.
Is there a cure other than bringing in a portable humidifier? (I've cleaned the machine.) I've never found humidifying a room useful.
I would like to purchase a new laser printer with a USB connection, but am reluctant to do so if static will be a continuing problem.
BTW, my ink jet printer does not have this problem.