Thinking of buying a used CLJ 5500dtn or 5550dtn - what to check for?

[Swampfoot]

A few questions -

- can it be made to work with Windows 10 or Windows 7?
- is there a way to get the menus to display the print counts?
- I can see in the manual how to tell it to print a test page, but can I get it to print a 12x18 test page? (I'll bring my own paper)
- from the unit's menus, can I tell it to print variously sized JPG files from a USB key?
- any other tests I can perform to put it through its paces? I can bring a laptop with a USB cable if necessary, with driver pre-installed. Also can print from within InDesign, CorelDraw, Photoshop, whatever.

They're asking $300. Have questions into the guy but still waiting for answers as to whether it's refurbed, has full carts, etc.
It's not going to be used in a commercial environment, just a personal goofing-off toy for as long as it lasts.

Thanks for any help!

[Lance15]

- can it be made to work with Windows 10 or Windows 7?
Download and install the HP UPD from HP's website

- is there a way to get the menus to display the print counts?
On the control panel? Not that I know of. You can have it display the IP address, though.

- I can see in the manual how to tell it to print a test page, but can I get it to print a 12x18 test page? (I'll bring my own paper)
Not specifically for tabloid (11x17). Test pages will print on tabloid.

- from the unit's menus, can I tell it to print variously sized JPG files from a USB key?
Printer does not have a walk-up USB port.

- any other tests I can perform to put it through its paces? I can bring a laptop with a USB cable if necessary, with driver pre-installed. Also can print from within InDesign, CorelDraw, Photoshop, whatever.
Print the PQ Diagnostic pages from the Diagnostic heading in the menus. It will print from whatever application as long as the driver is loaded and configured.