HP 4700 PRINTING FADED COLOR

SOURCE: HP Photosmart C6180 All-In-One Is printing All Documnets Faded Colors

Try to clean your printheads or check the level of your inks, maybe you are low on inks. Operating system does not affect any printing outputs as I know. Check your inks also coz HP cannot guarantee the quality or reliability of non-HP ink. If ink cartridges have been refilled, try replacing them with genuine HP ink cartridges.
If the print defect is minor, it might be caused by reserve mode operation. When the printer runs out of some colors, it can continue printing using remaining inks, but print quality may be affected. If cyan, magenta, or yellow is out, the printer can print only in grayscale.
Replace any empty print cartridges. To check ink levels, follow the steps below.

1. Press the Setup button.
2. Press the down arrow button until Tools is highlighted.
3. Press OK .
4. The Display Ink Gauge selection should be highlighted. Press OK and the ink gauge will display.

1. Open the printer Toolbox :

• Open HP Solution Center (click Start , then All Programs , then HP , then HP Solution Center ).
• If you have more than one printer installed, make sure to select the correct printer tab in HP Solution Center .
• Click Settings .
• Click Print Settings .
• Click Printer Toolbox .

1. Open the All-in-One Toolbox :
   1. Open HP Solution Center (click Start , click All Programs , click HP , and then click HP Solution Center ).
   2. If you have more than one All-in-One installed, make sure to select the correct All-in-One tab in HP Solution Center .
   3. Click Settings .
   4. Click Print Settings .
   5. Click Printer Toolbox .
2. On the Device Services tab, click Clean the Print Cartridges , and then follow the onscreen instructions. Three levels of cleaning are available.

SOURCE: HP 2605dn laser - color fading

HP has a list of troubleshooting steps you can go through for the HP 2605dn when you experience print quality issues.

Two specific things I would try from that list are:

1. Clean the electrostatic transfer belt.
2. Clean the printer paper path.

SOURCE: HP OfficeJet K80 won't print color anymore

Remove the printer from the systema and reinstall the latest driver from the manufactures website. Then re install the printer to your computer.

SOURCE: HP c3180 color printing problems

I would definitely start by printing a self-test page. With your model press and hold the Cancel button and then press the Start Color Copy button and then release both buttons. When this page comes out you should be able to identify the 4 different color sections...black, cyan, magenta and yellow. If any of these seperate areas are choppy or non-existant, you need to replace your cartridge. Here is a link that will show you examples of what you should/shouldn't see on the self-test report.

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00661556&lc=en&dlc=en&cc=us&product=1146331&rule=25470&lang=en

SOURCE: After cleaning the entire printer, per hp

Your drum alignment is wrong
the drum is one tooth shifted on one side ( most right side )