123.hp.com/ojpro8600. 123hp.info simply assist customers to Setup, Install and Troubleshoot HP Officejet model Printers. Get your printer connected to a MAC Device and begin to print A1 Class pictures with rich quality and High Definition and print them flawless.123.hp.com/ojpro8600. If print jobs are stuck in the print queue, then cancel all the documents in the queue and reboot the computer. Try printing a page after the reboot process is done. If your ojpro8600 printer switches off during printing, then an alert message should pop up on your computer screen. If it doesn’t, then there is a problem in the HP software that you have installed. Uninstall the software and reinstall it to avoid further problems.