HP Color Laserjet 2840 "Install Supplies" when black cartridge is installed, won't print

[Tekuri]

Got a 2840 free from my office. The thing is a beast and does not fit in my little office/toddler playroom at home. It was so heavy, and ran out of black ink just a month after bringing it home. I removed the Cyan, Magenta, and Yellow cartridges from it, ordered a new black Q3960A cartridge from eBay, and just installed it. However, the printer doesn't recognize it's there, as the screen just says "Install supplies" and has a ? above each cartridge symbol (CMYK). The orange ! light to the right of the display keeps flashing, and it won't print a test page or anything because it's not recognizing my new cartridge, that was new and still in it's original HP box. Please help!

[east2100]

There's a solenoid seats on top right of all four toner cartridges which is often gets stuck and makes many troubles like yours and printing all blank or all yellow.......

You'd better fix it first then you will find most of your printer's problems will go away.

http://westhillprinters.blogspot.com/2011/12/sticky-solenoids.html

You need to take the 2840 apart to get to the solenoid.

You can find out how to do it from YouTube and becides 2840 the HP 2500/2550/1500 are all have the same structure.

https://www.youtube.com/watch?v=a00l03VdhcA

https://www.youtube.com/watch?v=9BoxmagIjhg

Google and download the 2840's service manual it will help.