Troubleshooting

Laser Printers

Consistent or Repeated Marks on Page
If you have evenly spaced marks, vertical lines or splotches that consistently appear on the same side of the page then generally your drum needs to be replaced. Ask yourself - how old is the drum? If you have printed more than 10,000 pages then chances are the drum does need replacing. However, cleaning may help - the drum can be cleaned with isopropyl alcohol and a lint free cloth but take care not to touch it with your hands or exposing the drum to light for more than a few minutes. Wait 15 minutes to dry.

Random black vertical lines
A dirty cartridge corona wire is the most likely cause of random black vertical lines. To solve this, clean the wire with the tools that came with your printer - usually a built in "tab" cleaner or a brush supplied. Check your printer manual. If the vertical lines do not go away, it is possible an electrical charge is jumping across the corona wires. The cartridge needs to be replaced.

Variable Print Density
This is a common problem and is usually a sign that your toner cartridge is nearly empty. Replace the toner.

Random Splotches
This means the printer is dirty and needs cleaning. Possibly the cartridge waste bin is overfilling and is dumping toner back onto the drum.

Problem Printing Graphics or Duplex (double sided)
If your laser printer is very slow printing graphics or doesn't print the final part of the page, the memory of your printer may be too low. The memory required for duplex printing is also much higher than usual.

Inkjet Printers

Horizontal Lines Appearing
For Epson Inkjet troubleshooting go to Troubleshooting Epson Inkjets.
If horizontal lines start appearing, especially over lines of text, the ink carriage may need to be cleaned. The carriage is the assembly into which the ink cartridges are mounted that moves from side to side. After much use, ink builds upon the bottom of this assembly and drags marks across the paper as it is printing, leaving streaks or lines across the paper.
To clean, move the carriage into the cartridge replacing position (on most printers this is achieved by simply lifting the cover). Remove the cartridge(s) and use cotton swabs with a mild cleaning solution to thoroughly wipe the bottom of the carriage frame, especially towards the rear of the printer, until no more ink is removed. Replace ink cartridges and close the cover.

Printer acts like it's printing but nothing is printing onto the Paper
If you have used the cartridge for some time, this usually means the cartridge is out of ink. If you have just refilled a cartridge, possibly the cartridge has not been equalised properly. Repeat the instructions that came with the refiller.

Colours look strange. For example some greens look yellow, reds look purple.
The cartridge has one or more of its colours running out of ink. Try a new cartridge.

Nothing happens when trying to print
Check the printer is on and that the cable hasn't become disconnected. Another possibility is that the selection for colour vs grayscale is incorrect. Select File Print from your application and check the printer properties are set up according to the type of cartridge you are using.

Shutting Off the Printer
Most models of inkjet printers clean and park the printhead after if prints and when it is turned off. This operation can be heard as the head moves to it's "parking spot" and often takes up to 20 seconds to complete. The reason it does this is to seal the printhead from exposure to air to prevent it from drying out. If power to the printer is cut off before this operation is complete, the unsealed printhead may dry out causing blockages or streaking.

To avoid this, be sure to let the printer complete it's routine before shutting the power off to the printer.

Paper

Curling Photocopier Paper
This is usually caused by moisture in high humidity conditions, but the level of curling may depend on the quality of the paper used. Try a fresh ream as the wrapping of each ream is designed to keep the moisture out. If this doesn't work, try a higher quality of paper such as Reflex or Canon General Purpose