HP Photosmart C4780 - Manual (Page 97)

If the message does not indicate which cartridge is causing the problem, follow these
steps to determine which cartridge is the problem cartridge. After you determine which
cartridge is the problem cartridge, continue with the first solution.
To determine which print cartridge is having the problem
1. Make sure the product is on.
CAUTION: If the product is turned off when you open the print cartridge door to
access the print cartridges, it will not release the cartridges for changing. You
might damage the product if the print cartridges are not docked safely when you
try to remove them.
2. Open the print cartridge door.
The print carriage moves to the far right side of the product.
3. Check to make sure you are using the correct print cartridges for your product. For a
list of compatible print cartridges, see the printed documentation that came with the
product.
4. Remove the black print cartridge from the slot on the right.
Press down on the cartridge to release it, and then pull it toward you out of the slot.
1 Tri-color print cartridge
2 Black print cartridge
Errors 95
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