I just upgraded to Yosemite. I have a MacBook Pro purchased this April. I cannot print from Photoshop to my HP designjet T520 24" printer. Photoshop prints to my laser printer and InDesign and Word print to the T520. When I click on print in Photoshop to send to the T520 nothing happens. I have reset my PRAM and SMC on the computer. I have defaulted my prefs in Photoshop. What else can I do?
Check with HP for driver updates.
But what you are describing is a problem with the driver communicating with the printer - so you may need to contact HP for additional help.