Out of the blue, SWMBO's iMac has stopped working with my HP 2025dn color laser printer.

Since I know next to nothing about those spawn-of-the-devil Macintosh computers , I am at a loss how to continue.

By fumbling around with the iMac I managed to come up with a nonsensical error window saying the printer was out of toner (see attachment #1), but the printer has three new and one lightly used (maybe 100 pages) toner cartridges that cost more than the printer did when it was new. (See attachment #2.)

If the iMac is talking to the printer enough to think it is out of toner, does that mean it is not a connectivity problem? Or do iMacs behave like Windows machines and sometimes give out error messages that bear little or no relationship to the actual problem?

I can't provide much intelligent information about how the iMac is actually connected to the printer. There is an Ethernet cable that runs from an Ethernet port on the back of the iMac to my WRT54G2 router, and another Ethernet cable that runs from the router to the printer. My Windows computer is connected by Ethernet to the router and prints with no problems.

I tried switching the iMac to a different router port, but that did not change the behavior.

The only other bit of information I have is that when we put together the network printing a year or so ago I paid an Apple expert (compared to me, anybody who had ever even typed on an Apple is expert!) to set it up, and he ended up making a separate "Apple" account on my Windows machine that the iMac connects through to get to the printer. I don't know how that works, it's all magic to me.

What should I look for to fix this problem?

tanstaafl.