I have a hp6980 printer won't print says cartridge problem with rt hand black cartridge. It's trying to print then rt hand cartridge light comes on, flashes and it won't do anything

Main Cartridge is black it is required for printing it is not possible to print black with other cartridge.

Try it.......

Remove the print head and soak it for three 5-minute cycles in hot (~170 F) distilled water about 3/4 inch deep with continuous mild agitation. The first soak quickly turn the water black, the second end with the water a dark grey color. The hot distilled water dissolved the dried ink in the small ink passages from the cartridges to the ink ejection part of the print head.
Carefully dry the print head as per instructions, clean the electrical contacts on the printer, and placed the print head and the ink cartridges in the printer.Turn off the printer, then unplugged it for one minute.Then turn it on...and print an alignment sheet...

If you need any technical help on printer then you can reach at http://www.vtechsquad.com/

hi..........

In this error condition, the following light pattern displays on the product control panel and a message might display on the computer:

• Print Cartridge status light : On
• Resume light : Off
• Power light : On

Figure 69: The Power light is on and the Print Cartridge light blinks

Causes
• The cover on the product might be open.
• There might be a problem with one or both cartridges.

Solutions Follow these solutions in the order presented to resolve the issue. Solution one: Close the top cover on the printer

1. If the cover on the product is open, close it.
2. Press the Resume button ( ) to continue printing.

Solution two: Determine the cartridge issue When there is an issue with a cartridge, a yellow arrow on top of the carriage (inside the product) points to a drawing of a cartridge that indicates what the issue is. Follow these steps to determine the cartridge issue, and then continue to the next section for solutions to resolve the issue.

1. Open the top cover on the product. Wait for the carriage to move. The yellow arrow on top of the carriage (inside the product) points to a drawing of a cartridge that indicates what the issue is.
2. Look at the drawing and then find the icon in the following figure that matches the drawing. Each of these icons represents a different cartridge issue. Use the icons to determine the cartridge issue. Figure 70: Determine the cartridge issue 1 - Tri-color Cartridge Problem icon 2 - Black Cartridge Problem icon 3 - Tri-color Cartridge Low-ink icon 4 - Black Cartridge Low-ink icon 5 - Cartridges OK icon

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here's a solution i came across when dealing with the same problem. apparently the printer expects all of the cartridges to be full and has a sensor to make sure they are even when only printing black. hope this helps!

http://journal.drfaulken.com/trick-your-brother-inkjet-into-working-when-an-ink-cartridge-runs-dry/

that is because ur head of ur printing cartridge is damaged.

remove ur cartridges black as well as color
n install only black cartridge n check d blinking of lights on ur printer if it doesn't blinks it's mean ur black cartridge is OK but ur blinking of light on ur printer is same it's mean ur head of black cartridge is damaged
after this process remove the black one cartridge and install the color one cartridge n check d blinking of lights on ur printer if it doesn't blinks it's mean ur color cartridge is OK but ur blinking of light on ur printer is same it's mean ur head of color cartridge is damaged
now take a dry cotton cloth n gently clean ur cartridges head install both cartridges on ur printer n check ur blinking light on ur printer that will work only if u r too lucky other wise u have to purchase a one cartridge.

your black ink cartridge got bad sprayer nozzles now you gotta replace it
and why the other color one is not bad yet cus printer as will known will depend on black ink far more so the black cartridge is heated up more times

You have to refill both.

Regardless of whether you have printer set to print in black and white, these models will not function without usuable cartridges in all slots.

clean the contacts of cartridge carrier (the place you put cartridges in ) with a wet towel 

I have an HP Photsmart C4100 printer. I purchased remanufactured ink cartridges (both black and tri-colored) from Vivasmart. The black one works fine, but when I installed the tri-color, I got an error message that says "Print cartridge problem" The following print cartridge has a problem:
Tri-color. And I can't print. The screen on my printer says "Remove and check color cartridge." I have done this several times and it still won't print. I have turned off the power, removed the cartridges, and unplugged the unit, but it still didn't help. Any suggestions?