Lets plug in some numbers. Today I checked prices of aforementioned OEM cartridges on Staples web site.

HP 51645A - $29.99 HP C6578AN - $54.99

Our HP790C3B kit refills:

Black - 3 times Color - 5 times

The kit sells for $27.95.

Here is formula with numbers plugged in:

S = (5 x 54.99) + (3 x 29.99) - 27.95 S = (274.95) + (89.97) - 27.95 S = 364.92 - 27.95 S = 336.97

Quite an eye opener isn't it? By spending $27.95 you can save $336.97. I would get some ink on my hands to save $337.00!

I believe wholeheartedly that if more people knew how much money they can save there would be a lot less of these cartridges ending up in landfills.

Just please remember, start small. If you've never refilled before don't start by ordering a gallon of ink.

If all seems well with printer it's time to check wire that connects printer to computer. You may be using a parallel or a USB connection. Make sure cable is connected properly. Turn equipment off and remove and re-insert connection on both printer and computer to ensure a solid connection. If you are at work and your printer is connected to what appears to be a telephone wire then it's time to call your resident network expert.

If printer works but only prints garbage then that is a good indication of a printer driver problem. The printer driver is a software program that translates computer instructions into something that printer can recognize. Try re-booting computer and turning printer off and on before messing with driver. Sometimes that's all it takes. If after doing that you still have problem it's time to replace printer driver. Your printers manufacturer has a web site where you can download another printer driver. They are free to download and usually are updated as well. Follow instructions given by manufacturer to replace your driver.

If you have a scanner it may be interfering with your printer. Try reinstalling software for both BUT install printer driver first, then scanner driver.

If nothing I've said results in a solution then it may be time to call printer manufacturer. Make sure that you are near printer when you call and have all your warranty information available.