HP OfficeJet Pro K850 User Manual

							Testing media skew
If information on the printed pages is consistently slanted, perform a paper skew test and check if the
skew is within the acceptable range for the printer.
●Printer driver
Click the Services tab, click Service this device, and then follow the onscreen instructions.
●Toolbox (Windows)
Click the Printer Services tab, click Test Paper Skew, and then follow the onscreen instructions.
●HP Printer Utility (Mac OS)
Open Information And Support, click Test Paper Skew, and then follow the onscreen
instructions.
ENWWTesting media skew 73
 
						

							Calibrating the color
Whenever you replace a printhead, the printer automatically calibrates the colors to ensure the best
print quality. If you are not satisfied with the appearance of the colors, you can calibrate colors
manually.
●Printer driver
In Windows 2000 or XP, click the Services tab, click Service this device, and then follow the
onscreen instructions.
In Windows 98, click the Services tab, click Calibrate Color, and then follow the onscreen
instructions.
●Toolbox (Windows)
Click the Printer Services tab, click Calibrate Color, and then follow the onscreen instructions.
●HP Printer Utility (Mac OS)
Open Information And Support, click Calibrate Color, and then follow the onscreen instructions.
74 Chapter 5   Maintaining and troubleshooting ENWW
 
						

							Troubleshooting
Troubleshooting tips and resources
●For a paper jam problem, see Clearing jams.
●For paper-feed problems, such as the paper skew, see 
Resolving paper-feed problems.
Some printer problems can be resolved by resetting the printer.
To reset the printer
1.
Press 
 (Power button) to turn off the printer.
2.Disconnect the power cord from the printer.
3.Wait about 10 seconds, and then reconnect the power cord.
4.
Press 
 (Power button) to turn on the printer.
General troubleshooting tips
Ensure the following:
●Power light is on and not blinking. When the printer is first turned on, it takes approximately 45
seconds to start up.
●No error messages appear on the computer screen.
●No lights on the control panel are on or blinking. See 
Printer lights reference.
●Power cord and other cables are working and firmly connected to the printer. Make sure the
printer is connected firmly to a functioning alternating current (AC) power outlet and is turned on.
See 
Printer specifications for voltage requirements.
●Media is loaded correctly in the tray and is not jammed in the printer. See 
Loading media.
●Printheads and ink cartridges are properly installed in their correct color-coded slots. Press down
firmly on each one to ensure proper contact. Ensure you have removed the tape from each
printhead.
●Printhead latch and all covers are closed.
●Rear-access panel or automatic two-sided printing accessory (duplex unit) is locked into place.
●All packing tapes and materials are removed from the printer.
●Printer can print a configuration page. See 
Understanding and printing the configuration page.
●The printer is set as the current or default printer. For Windows, set the printer as the default in
the Printers folder. For Mac OS, set the printer as the default in the Print Center or Printer Setup
Utility. For more information, see your computers documentation.
●Pause Printing or Use printer offline is not selected if you are using a computer running
Windows.
●You are not running too many programs when you are performing a task. Close programs that
you are not using or restart the computer before attempting the task again.
ENWWTroubleshooting 75
 
						

							●If the printer is connected directly to a computer, it is set up to point to the correct port.
●If the printer is connected to a network, the correct IP address is used.
Resolving printing problems
Printer shuts down unexpectedly
Check power and power connections.
Make sure the printer is connected firmly to a functioning alternating current (AC) power outlet. See
Printer specifications for voltage requirements.
All printer lights are blinking 
A non-recoverable error has occurred.
Reset the printer. See 
Troubleshooting.
If the problem persists, contact HP. See 
Support and warranty.
Printer is not responding (nothing prints)
Check printer setup
See 
General troubleshooting tips.
Check the printhead initialization
When new printheads are installed, the printer automatically prints two alignment pages to align the
printheads. This process takes about eight minutes. Once the process starts you cannot print until
the automatic alignment pages have been printed.
When printheads are removed and then reinserted in the printer, the alignment pages do not print
automatically. See 
To align the printheads.
Check the printer software installation
If the printer is turned off when printing, an alert message should appear on your computer screen;
otherwise, the printer software might not be installed correctly. To resolve this, uninstall the software
completely, and then reinstall the printer software. See 
Uninstalling the printer software.
Check cable connections
●Make sure both ends of the cable (USB, parallel, or network) are secure.
●If the printer is connected to a network, check the following:
●Verify that the Link light on the back of the printer is on.
●Make sure you are not using a phone cord to connect the printer.
●The network hub, switch, or router is on and working properly.
76 Chapter 5   Maintaining and troubleshooting ENWW
 
						

							Check printer setup for network environment
Ensure the correct printer software and printer software port are being used. For more information
about network connections, see 
Configuring the printer (Windows), Configuring the printer (Mac OS),
or the documentation provided by your network vendors.
Check any personal firewall software installed on the computer
The personal software firewall is a security program that protects a computer from intrusion.
However, the firewall might block communication between the computer and the printer. If there is a
problem communicating with the printer, try temporarily disabling the firewall. If the problem persists,
the firewall is not the source of the communication problem. Re-enable the firewall.
If disabling the firewall allows you to communicate with the printer, you might want to assign the
printer a static IP address and re-enable the firewall. See 
Configure network options.
Printer does not accept printhead
Inspect the printhead
Remove the printhead and make sure the protective tape has been removed completely from the
printhead.
Clean the printhead
Complete the printhead cleaning procedure. See 
To clean printheads automatically.
Turn off the printer after removing the printhead
After removing the printhead, turn the printer off, and then turn on the printer without the printhead
installed. After the printer has restarted, reinsert the printhead.
Printer takes a long time to print
Check the system configuration
Make sure the computer meets the minimum system requirements for the printer. See 
Printer
specifications.
Check the port setting
The port setting configuration in your system might not be set to ECP.
See the documentation that came with the computer for information on how to change the port
setting, or contact the computer manufacturer.
Check the printer software settings
The printer prints slower when Best or Maximum dpi is selected as the print quality. To increase the
print speed, select different print settings in the printer software. See 
Changing print settings.
NOTEThe recommended print quality setting for printing photos is Best.
Blank page printed
ENWWTroubleshooting 77
 
						

							Check media settings
Make sure the page settings in the printer software matches the width and length of media loaded in
the tray. See 
Changing print settings.
Check the parallel port on your computer
If you are using a parallel cable, make sure the printer is connected directly to the parallel port. Avoid
sharing the port with other devices, such as a Zip drive or other printers.
Placement of the text or graphics is wrong
Check how the media is loaded
Make sure the paper guides fit snugly against the edges of the stack of media, and make sure the
tray is not overloaded. See 
Loading media.
Check the media size
●Content on a page might be cut off if the document size is larger than the media that you are
using.
●Make sure the media size selected in the printer driver matches the size of media loaded in the
tray.
●If you are using a computer running Windows, select Emulate LaserJet Margins in the printer
driver to print a LaserJet formatted document.
Check margin settings
If the text or graphics are cut off at the edges of the page, make sure the margin settings for the
document do not exceed the printable area of your printer. See 
Setting minimum margins.
Check the page-orientation setting
Make sure the media size and page orientation selected in the application match the settings in the
printer driver.
Check the Preserve Layout setting (Windows)
If you are using a duplex unit to do automatic duplex printing, ensure Preserve Layout is selected in
the printer driver. Clearing this option might result in unwanted page breaks. See 
Printing on both
sides (duplexing).
Check the printer location and length of USB cable
High electromagnetic fields (such as those generated by USB cables) can sometimes cause slight
distortions to printouts. Move the printer away from the source of the electromagnetic fields. Also, it is
recommended that you use a USB cable that is less than 3 meters (9.8 feet) long to minimize the
effects of these electromagnetic fields.
If the solutions do not work, the problem might be caused by the inability of the application to
interpret print settings properly. See the release notes for known software conflicts; or refer to the
applications documentation, or contact the software manufacturer for specific help.
78 Chapter 5   Maintaining and troubleshooting ENWW
 
						

							Poor print quality and unexpected printouts
Check the printheads and ink cartridges
Replace any clogged or worn printheads or low ink cartridges (see Maintaining the printheads), and
try to print again.
Check the paper quality
The paper might be too moist or too rough. Make sure the media used meets HP specifications (see
Selecting print media), and try to print again.
Check the type of media loaded in the printer
●Make sure the tray supports the type of media you have loaded. See Understanding
specifications for supported media.
●Make sure you have selected the tray in the printer driver that contains the media you want to
use. See 
Changing print settings.
Check the printer location and length of USB cable
See Check the printer location and length of USB cable.
Meaningless characters print
If an interruption occurs to a job that is printing, the printer might not recognize the rest of the job.
Cancel the print job and wait for the printer to return to the ready state. If the printer does not return
to the ready state, cancel all jobs, and wait again. When the printer is ready, resend the job. If
prompted by the computer to retry the job, click Cancel.
Check cable connections
If the printer and computer are connected with a USB or parallel cable, the problem might be due to
a poor cable connection or a cable that is not in working condition.
Make sure the cable connections at both ends are secure. If the problem persists, turn off the printer,
disconnect the cable from the printer, turn on the printer without connecting the cable, and delete any
remaining jobs from the print queue. When the Power light is on and not flashing, reconnect the cable.
Check the document file
The document file might be damaged. If you can print other documents from the same application,
try printing a backup copy of your document, if available.
Check the symbol set
If you are using MS-DOS, use the HP DJCP to set the appropriate symbol set for the language of
your document. See 
HP Deskjet Control Panel (HP DJCP).
Ink is smearing
ENWWTroubleshooting 79
 
						

							Check print settings
●When you print documents that use a large quantity of ink, allow more time to dry before
handling the printouts. This is especially true for transparencies. In the printer software, select
the Best print quality. Also increase the ink drying time and reduce the ink saturation using an
ink slider in conjunction with drying time under Advanced Printing Features (Windows) or Ink
Features (Mac OS) in the printer software. However, note that decreasing ink saturation might
give printouts a washed-out quality.
●Color documents that have rich, blended colors can wrinkle or smear when printed using the
Best print quality. Try using the other print mode to reduce ink, or use HP Premium Paper
designed for printing vivid color documents. See 
Changing print settings.
Check the media type
●When using recycled media, you might need to lower the ink volume in the printer software.
However, if you lower the ink volume too much, the output might appear washed out.
●Some types of media do not accept ink well; ink will dry more slowly and smearing might occur.
See 
Selecting print media.
Check the margin settings
If you are using a computer running Windows, make sure the option to minimize margins is not
selected.
Clean the inside of the automatic two-sided printing accessory
After extensive printing, ink might be deposited on the inside of the duplex unit causing ink to smear
when printing on both sides of the paper. To remove the deposited ink, use a lint free cloth to clean
the inside of the duplex unit.
80 Chapter 5   Maintaining and troubleshooting ENWW
 
						

							Clean the print zone of the printer
After extensive printing, ink might be deposited on the print zone of the printer, causing ink to smear
on the non-printed side of the media or the edge of a stack of printed media. To remove the
deposited ink, use a lint free cloth to clean the print zone, including the plastic ridges.
Enable the printers output ramp
When printing in Fast Normal (default) print mode, the printer does not use the output ramp to hold
each printed page before releasing it onto the output tray. If the printer starts printing the next page
while the printed page is still drying on the output tray, the newly printed page might rub against the
printed page on the output tray, causing ink to smear. Severity of smearing depends on the amount
of ink used on each printed page.
To prevent the printed pages from rubbing against each other, print using the Normal or Best print
mode.
Alternatively, in the Toolbox, turn on the output ramp for printing in Fast Normal mode. Click the
Printer Services tab, and then click Configure Output Ramp. See 
Toolbox (Windows).
ENWWTroubleshooting 81
 
						

							Ink is not filling the text or graphics completely
Check the ink cartridges
Ink cartridges might have run out of ink. Replace any empty cartridge. Or try removing and
reinstalling the cartridges, make sure they snap firmly into place. See 
Replacing the ink cartridges.
Check the media type
Some media types are not suitable for use with the printer. See 
Selecting print media.
Output is faded or dull colored
Check the print mode
The Fast Normal printer mode allows you to print at a faster rate. It is good for printing drafts. For
better results, select Normal or Best. See 
Changing print settings.
Check the paper type setting
When printing on transparencies or other special media, select the corresponding media type in the
printer driver. See 
Printing on special and custom-size media.
Check the ink cartridges
If lines in the text or image are broken or do not print properly, one or more of the ink cartridges
might have run out of ink or are defective. Replace these cartridges with new ones.
Colors are printing as black and white
Make sure Print in Grayscale is not selected in the printer driver.
Wrong colors are printing
Check print settings
Make sure Print in Grayscale is not selected in the printer driver.
Check the printheads
Whenever print quality noticeably decreases, you might need to clean the printheads. See
Maintaining the printheads.
Printout shows bleeding colors
Check print settings
Some media type settings (such as Transparency Films and Photo Papers) and print quality
settings (such as Best) require more ink than others. When you choose different print settings in the
printer driver, make sure you select the correct media type. See 
Changing print settings.
82 Chapter 5   Maintaining and troubleshooting ENWW