HP's "revenue security" system involves date stamping cartridges on first use - they last for at most 18 months, then you have to replace them.
If you look at a cartridge, you'll find it's no more than a piece of fancy sponge in a plastic box - the chip on the back is simply glued on.
My first attempt to get round the date stamp was to simply remove the chip - no such luck, HP thought of that one.
The correct, and tested by me, way to get round it is to remove or isolate the internal battery. The sole function of the printer's battery is to maintain a clock. I suspect it is a real-time clock, because cartridges have a 'use by date' coded at the factory and printed on the box. How it gets the current date from the PC is a mystery to me, but likely to be linked with the HP Tools application or the print driver.
I have removed my battery (used it in another device whose battery was flat - no wastage here!) with no adverse affects at all.
You really need a Torx to fit the HP screws, but I got away with a long, thin steel bar ground carefully into a triangular end with an angle-grinder.
Some of the screws and clips are very difficult to reach - take the time to find or make the right tool or you'll damage the casing.
On an HP cp1160, with the printer facing you, the battery is located below the control panel at the very left edge of the PCB. It's difficult to see, and even harder to reach. You should only need to remove the top half of the casing and the control panel. Don't remove any of the print carriage or the main circuit board. If you can't remove the battery, wedge a thin strip of hard plastic between it and the contacts - a long plastic bottle would do, cut up.
I have also found that print heads can be restored fully by running them under the hot tap, both from the ink supply end and from the jet end alternately. What appears to happen is the ink only dissolves well when the temperature is high enough. I didn't attempt to dry the print head because they are physically fragile. Once you dry the casing and contacts, stick it straight back in the printer and run the cleaning routine to replace any water with ink. I expected to have to go through a lot of cleaning and priming once back in the printer, but it only needed one clean to give solid colours. This print head is now over five years old and still going.
Please mail me if you have any questions or need clarification.
If you look at a cartridge, you'll find it's no more than a piece of fancy sponge in a plastic box - the chip on the back is simply glued on.
My first attempt to get round the date stamp was to simply remove the chip - no such luck, HP thought of that one.
The correct, and tested by me, way to get round it is to remove or isolate the internal battery. The sole function of the printer's battery is to maintain a clock. I suspect it is a real-time clock, because cartridges have a 'use by date' coded at the factory and printed on the box. How it gets the current date from the PC is a mystery to me, but likely to be linked with the HP Tools application or the print driver.
I have removed my battery (used it in another device whose battery was flat - no wastage here!) with no adverse affects at all.
You really need a Torx to fit the HP screws, but I got away with a long, thin steel bar ground carefully into a triangular end with an angle-grinder.
Some of the screws and clips are very difficult to reach - take the time to find or make the right tool or you'll damage the casing.
On an HP cp1160, with the printer facing you, the battery is located below the control panel at the very left edge of the PCB. It's difficult to see, and even harder to reach. You should only need to remove the top half of the casing and the control panel. Don't remove any of the print carriage or the main circuit board. If you can't remove the battery, wedge a thin strip of hard plastic between it and the contacts - a long plastic bottle would do, cut up.
I have also found that print heads can be restored fully by running them under the hot tap, both from the ink supply end and from the jet end alternately. What appears to happen is the ink only dissolves well when the temperature is high enough. I didn't attempt to dry the print head because they are physically fragile. Once you dry the casing and contacts, stick it straight back in the printer and run the cleaning routine to replace any water with ink. I expected to have to go through a lot of cleaning and priming once back in the printer, but it only needed one clean to give solid colours. This print head is now over five years old and still going.
Please mail me if you have any questions or need clarification.
