Our office's HP4650dn started printing images that fade from left-to-right yesterday. The text is crisp and dark on the left and largely unreadable on the right. Here's the trippy aspect of the faded print jobs: They only occurs when printing from some apps.
Office Tracker - We use a program called Office Tracker for scheduling. When printing from Office Tracker, the page fades about 90% of the time.
Word - Print jobs coming from MS Word fade about 50% of the time.
Access - Print jobs coming from MS Access fade about 50% of the time.
Print Test Page - Print jobs coming from Printer Properties / Print Test Page never fade.
The fade effect occurs for all client machines printing to the HP 4650dn. These include XP, Windows 7, and Windows 8 machines. I had set up logical printers on the network using both PCL and PostScript. The fade effect occurs with both PCL and PostScript. I swapped the PCL driver to the most the most recent driver (HP Universal Print Driver for Windows PCL6, v 5.7.0). The fade effect still occurs.