HP Printer oddity question

I have a HP 940c printer, it is about a year and a half old. I don’t do a lot of printing, but a couple months ago I noticed my cartridges were getting low. The color was down to about 3%, the black was at 15%. The cartridges had been in he printer since the day I bought it. So I went and bought new cartridges to replace the originals.

I changed the color cartridge first, since it was at 3%, and figured I would change the black when it got lower - no sense in wasting a 15% full cartridge. I changed the color, and checked it in the tool box ink level thing - and not only was the color at 98% (after doing an alignment), but the black was at 99%.

I thought it was a fluke, and it would change after a reboot or a few more print jobs. I forgot about it and checked it today, and it is still holding at 89% full!

What gives? I do a mix of printing, mostly text in B&W, but sometimes I print photos out.

Where are you getting the % figures from ? If it’s from software, it’s perhaps a calibration error.

Take out the black cartridge, shake it (gently), and determine the amount of ink physically left in the cartridge. Shake the new black one and see the difference. Weigh the two black ones and see the difference. You’ll get an idea of howmuch is actually left in the black cartridge.

The software has an estimated ink level thing.

I think you are right, a calibration error. I don’t print enough to be a printer expert. I took the cartridge out, but it was really hard to determine how full/empty it was, the cartridge itself is fairly heavy. I wrecked the copper cover putting it back into the printer :smack: so I just changed to the new one.

It was just weird, I wonder how long I could keep going on the original black cart?

89% more, obviously.

Well, now that you’ve wrecked it… why not go all the way.

Things you’ll need:

  1. Hammer.

Crack open the cartridge, drain out the ink. More splashes the better. Hold a graffiti competition for the kids, even. This way we’ll know exactly how much ink was left inside.

I don’t know about your printer, but some printers don’t actually measure how much ink is in the cartrige, but work it out from how much printing you’ve done. Maybe, by realigning the heads, you managed to reset the ink total to 100%.

Maybe.

I can confirm HP printers don’t actually measure the ink in the cartridge (at least mine doesn’t) - it is estimated by the driver (which, in theory, knows exactly how many dots of each colour have been squirted) - mine said I was out of ink, but I kept going until there were missing bands on the output - at least a few dozen pages later.