Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
I think the problem is likely to be either settings or software (and if software, likely the printer driver installed) on the Mac computer(s).
Please tell me how long the problem has been showing up with printing, and whether it has worked fine before this with these same computers. (Depending upon your answers on these two points, it might be one or another problem in one or another place.)
(*If* the problem has not showed up until today or very recently, I advise you to treat it this way:
1. unplug the printer, while it is On, suddenly.
2. leave it unplugged, and meanwhile, restart *all* the computers (that print to it.)
3. leave it unplugged from power, for at least 1 hour or so (roughly that much time.)
4. Turn it Off if the power switch is still 'On', then plug it in again to the power, turn it On if necessary.
Try it again and see how it goes. If it is producing blank sheets to Tray C when printed to from computers, and is only doing this recently or only today, then this may well help.)
I see. I'm sorry there has been no improvement.
Try this - the logical next step:
Press MENU on the printer until Resets Menu appears,
Then select the Restore Factory Reset option and execute it. (If there is not exactly that option, look for 'Factory Reset', and execute that.
What paper size are Tray A and Tray B loaded with?
Pull out, remove and reload in each tray (except C, leave that one alone for now.)
At this point I am thinking either you have a printer problem requiring servicing, or an obscure setting... probably on the printer... and that admittedly seems much less likely at this point.
However the problem with the printer, if that's what and where it is, might be aided by a bit of tweaking, reloading and reseating. It's worth a try.
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