Why does my printer print fine but copy blank pages?

This usually happens because the scanner lamp is not exposing the image, the scanner lock is engaged, or the ADF strip is obscured.

Why do my copies have black lines running down the page?

This is almost always caused by a small speck of correction fluid, dust, or glue on the narrow glass strip used by the automatic document feeder.

Can I use regular window cleaner on my scanner glass?

Yes, but you should always spray the cleaner onto a soft cloth first rather than directly onto the glass to prevent liquid from seeping inside the scanner optics.

What is the difference between printing and copying regarding troubleshooting?

Printing only tests the print engine and data connection, whereas copying tests both the input scanner assembly and the output print engine.

Scanner ProblemsWorth attentionAbout 15 min

Printer Copy Problems: Blank, Dark or Failed Copies

Quick answer

When printing works normally but copying fails, the issue is isolated to the scanner assembly rather than the printer engine. Clean the scanner glass and ADF strip, check the scanner lamp, and reset the device to resolve copy errors.

Published 25 August 2026

What this means

If your computer prints documents normally but copying fails, the print mechanism is fine. The issue lives entirely in the scanning assembly, meaning trouble in the scanner glass, the scanner lamp, the document feeder, or the firmware.

You might assume a bad copy means the whole printer is failing or the ink system is broken. Printing and copying use separate pathways. A completely blank copy usually points to a disconnected or failing scanner lamp. If you see permanent vertical lines on your copies, do not blame the large flatbed glass. Those lines come from a smudge on the narrow secondary document feeder glass strip.

Other physical faults will break your copies while leaving computer jobs untouched. Worn document feeder rollers cause paper jams or multiple feeds. A locked scanner mechanism stops the internal capture elements from moving. Power fluctuations can even freeze the scanner controller board while the main print engine keeps working.

Common causes

Dirty scanner glass or ADF white backing
Defective or unseated scanner bulb or lamp
Automatic document feeder sensor obstruction
Corrupted firmware or scanner calibration
Loose internal scanner ribbon cable

What to check first

1Test printing a document from a computer to confirm the printer mechanism works
2Verify the original document is placed face down on the glass or face up in the ADF correctly

Step-by-step fix

1
Clean the scanner glass and ADF strip
Wipe the flatbed glass and the smaller ADF glass strip with a lint free cloth and glass cleaner.
Do not spray cleaner directly onto the glass.
2
Check ADF paper load and rollers
Ensure paper is loaded correctly in the ADF tray and clean the pickup rollers with a damp lint free cloth.
3
Power cycle the printer
Turn off the printer, unplug the power cord for sixty seconds, and plug it directly into a wall outlet.
4
Calibrate the scanner
Run the scanner calibration utility from the printer control panel or software utility.
5
Check the scanner lock switch
Ensure the physical scanner transport lock is unlocked if your model has a locking switch.
Forcefully moving a locked scanner mechanism can break the internal gears.
6
Update the printer firmware
Check the manufacturer website for any available firmware updates that address scanner logic issues.

When to contact a professional

Call a professional technician if your scanner lamp stays dark, makes a loud grinding noise during a copy, or has damaged internal ribbon cables. Disconnect the power before cleaning any internal areas. Never look directly into the active scanner lamp. Check your warranty status before you attempt advanced repairs, as opening certain parts may void your coverage.

Questions people ask

Why does my printer print fine but copy blank pages?: This usually happens because the scanner lamp is not exposing the image, the scanner lock is engaged, or the ADF strip is obscured.
Why do my copies have black lines running down the page?: This is almost always caused by a small speck of correction fluid, dust, or glue on the narrow glass strip used by the automatic document feeder.
Can I use regular window cleaner on my scanner glass?: Yes, but you should always spray the cleaner onto a soft cloth first rather than directly onto the glass to prevent liquid from seeping inside the scanner optics.
What is the difference between printing and copying regarding troubleshooting?: Printing only tests the print engine and data connection, whereas copying tests both the input scanner assembly and the output print engine.

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Not the problem you have?

Switch off and unplug a printer before reaching inside it. Steps that can damage hardware or affect a warranty are flagged above. If your machine is still under warranty, or the fault involves the power supply or internal electronics, contact the manufacturer or a qualified technician instead. Full disclaimer.

What this means

Common causes

What to check first

Step-by-step fix

Clean the scanner glass and ADF strip

Check ADF paper load and rollers

Power cycle the printer

Calibrate the scanner

Check the scanner lock switch

Update the printer firmware

When to contact a professional

Questions people ask

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