Imaging unit my printer keeps prompting me to install the imaging unit even though it's a new one, why?

if you use toner that says for use in instead of Kyocera brand toner this can happen you have to remove all the toner in the dv unit and install only Kyocera toner when you do that enter 1087 1087 then 130 and let it run until its done this will refill the dv unit with toner even though you have a copystar machine its made by Kyocera when it stops enter 01 then print to return to normal operating mode

what model ????????????????

Step Action Image 1 Ensure the All-In-One printer is powered on. No image. 2
Lift the scanner unit or access door (per right-hand image).
The cartridge holder will move to the center of the Inkjet or All-In-One.
3 Press down on the cartridge carrier latch to raise the carrier lid. 4 Remove the used cartridge. NOTE: If you are removing both cartridges, repeat the preceding two steps for the second cartridge. No image. 5
Remove the protective tape from the back and bottom of the new cartridge(s).
WARNING! Do not touch the gold contact area on the back or the metal nozzles on the bottom of the cartridges. 6a Insert the new cartridges into their respective carriers. The image at right illustrates inserting the color cartridge. 6b The image at right illustrates inserting the black cartridge. 7 Close the carrier lids so that they remain closed. See image above in Step 3. No image. 8 Close the access door or scanner unit, taking care to keep your hands out from underneath the scanner unit as it is being closed. No image. 9 On some All-In-One units, the control panel display will prompt you to load paper and print an alignment page. NOTE: The scanner unit must be closed before you can start a new scan, print, copy, or fax job. No image.

Hi there Jenny, are you using Vista with this printer? If yes, you can to the following:

1. Click the Vista Start button, and go to Control Panel
2. Click Hardware and Sound.
3. Under Printers, click Change default printer.
4. Right click on the printer icon, select Run as administrator, and then click on Properties.
5. If the User Account Control prompt is displayed, click Continue.
6. Click on the Ports tab.
7. Click Configure Port associated to your Brother MFC790c
8. Change the Protocol to Raw.
9. Then click OK.

Restart the printer and try again.

If this does not work, please let me know so that I can suggest other solutions. Goodluck!

Did you recently install new ink cartridges?
See below, or go here and enter your model # , choose tech support and search "change print cartridge" for detailed instructions with pictures.
Overview
This article provides general instructions on how to change the cartridges on Lexmark Inkjet and All-In-One printers.
Procedure
1 Ensure the All-In-One printer is powered on. No image.
2 Lift the scanner unit or access door (per right-hand image).
The cartridge holder will move to the center of the Inkjet or All-In-One.
3 Press down on the cartridge carrier latch to raise the carrier lid.
4 Remove the used cartridge. NOTE: If you are removing both cartridges, repeat the preceding two steps for the second cartridge. No image.
5 Remove the protective tape from the back and bottom of the new cartridge(s).
WARNING! Do not touch the gold contact area on the back or the metal nozzles on the bottom of the cartridges.
6a Insert the new cartridges into their respective carriers. The image at right illustrates inserting the color cartridge.
6b The image at right illustrates inserting the black cartridge.
7 Close the carrier lids so that they remain closed. See image above in Step 3. No image.
8 Close the access door or scanner unit, taking care to keep your hands out from underneath the scanner unit as it is being closed. No image.
9 On some All-In-One units, the control panel display will prompt you to load paper and print an alignment page. NOTE: The scanner unit must be closed before you can start a new scan, print, copy, or fax job. No image.
I hope this information allows you to resolve this issue. If you need further assistance, please post back with a comment to this thread.
If I've managed to answer your question or solve a problem, please take just a moment to rate this post....thanks!

How to Change the Cartridges on Lexmark Inkjet and All-In-One Printers ID: ENUS32244 Overview
This article provides general instructions on how to change the cartridges on Lexmark Inkjet and All-In-One printers.
Procedure

NOTE: These instructions are general, and your specific Inkjet or All-In-One may appear different than the pictures below; however, the steps are the same.
Step Action Image 1 Ensure the All-In-One printer is powered on. No image. 2 Lift the scanner unit or access door (per right-hand image).
The cartridge holder will move to the center of the Inkjet or All-In-One.

3 Press down on the cartridge carrier latch to raise the carrier lid. 4 Remove the used cartridge. NOTE: If you are removing both cartridges, repeat the preceding two steps for the second cartridge. No image. 5 Remove the protective tape from the back and bottom of the new cartridge(s).
WARNING! Do not touch the gold contact area on the back or the metal nozzles on the bottom of the cartridges.
6a Insert the new cartridges into their respective carriers. The image at right illustrates inserting the color cartridge. 6b The image at right illustrates inserting the black cartridge. 7 Close the carrier lids so that they remain closed. See image above in Step 3. No image. 8 Close the access door or scanner unit, taking care to keep your hands out from underneath the scanner unit as it is being closed. No image. 9 On some All-In-One units, the control panel display will prompt you to load paper and print an alignment page. NOTE: The scanner unit must be closed before you can start a new scan, print, copy, or fax job. No image. Still Need Help? If you require additional assistance, please contact Lexmark Technical Support. NOTE: When calling for support, you will need the machine/model type and serial number (SN) of your printer.
Please call from near the computer and printer in case the technician asks you to perform a task on one or both of these devices.

Usually the scanner and printer have separate drivers, even though both are included in one machine.

Check HP's website to see if there's a separate driver for the scanner or a program which installs both drivers from the same setup program. You might have to check device manager to see if a scanner is listed and if the driver is properly installed.

In XP and VISTA, go to control panel/device manager and see if there are any yellow caution signs by the 'imaging device' icon. If there is no 'imaging device' icon, either the driver is not installed or not installed properly.

One additional factor... HP usually requires that the driver be installed before the hardware is connected. After drivers are installed, New Hardware Wizard should find your HP devices and install them properly. If not, you might want to unistall them altogether and reinstall.

Hope this helps.

just go to control panel, add remove programs, select print shop (change) and select modify it will allow you to change content to hard drive and not cd.

possible toner pump