For refilling, you need:
- 4 syringes with needles
- ink: 1x black, 3x colour (cyan, magenta, yellow)
- paper towel or newsprint as underlay
- a cutter knife
Preparation:
Put the needles on the syringes. Draw in approx. 28ml of coloured ink and approx. 68ml of black ink and put the prepared syringes aside. Hold the cartridge as shown in picture 1 and pull out the sealing plug from the filler opening (right-hand side in the picture).
Refilling the refillable ink cartridge HP 940:
Insert the prepared syringe with needle straight into the cartridge (picture 2). Place the needle on the plastic bar inside the cartridge. Do not insert it further or else you could damage the cartridge! Fill the cartridge with ink up until 1cm below the upper edge of the cartridge, then reinsert the plug.
The refillable ink cartridges HP 940 are not equipped with a chip to monitor the filling level. Therefore, you need to remove the chip from the old cartridge and put it on the new one.
Exchanging the chip:
Carefully slip a cutter knife or a plain screwdriver between chip and cartridge body (picture 3) and use it as lever. Please be careful not to damage the chip. Now set the chip in the provided place on the refillable ink cartridge HP 940 (picture 4).
It is not possible to reset the chip on HP 940 cartridges. Therefore, it will signal that the cartridge is empty even if you just refilled it. You can ignore this message and continue printing, but you will no longer have a reliable ink level indicator. As soon as your printer starts producing streaky or otherwise unsatisfying printouts, you should cancel the print job immediately. Otherwise, the print head can overheat and be damaged.
Characteristics of refillable ink cartridges:
After successfully refilling the cartridge you can use it again. However, before reinserting the HP 940 cartridge into your printer, you have to remove the other plug (picture 1) labeled “air”. This is the ventilation opening which balances the pressure during printing to avoid the development of a vacuum.