I think there is a problem on the sensor that is reading the cyan ink. Please try below steps, to reset the sensor's thresholds for light and dark conditions.
If the routine above doesn't help, try cleaning the sensors, easily visible and accessible when the ink is out. Poke a pipe cleaner down into the sensor gap and twirl it a bit to brush out dust.
- Power-down the machine with the button on the front panel. Let it finish any cycling.
- Unplug AC power.
- Lift the right-hand end of the scanner to open the ink cartridge area.
- Pull back the white latch hooks to remove all four cartridges. Set the cartridges upright on the table.
- Brother says aftermarket ink cartridges may cause this problem. Make sure that all four cartridges are genuine Brother ink. Replace any generic ones before going farther.
- Check the levels of the ink visible in the cartridges. The machine has sensors that look through the clear rib in the right-hand side of each cartridge. Assuming you find all cartridges at least half-full:
- Leaving the machine open and empty of ink, plug in the power.
- The display will tell you it has no black ink, and to install a cartridge. Install the black ink.
- Following the color order on the display, reinstall each of the ink cartridges.
- Lower the scanner. You'll have to push in the top end of the blue support bar to start lowering it.
- The machine should come up ready.
If this still won't work, resetting the memory in Maintenance Mode might help:
If you still have the problem, you may have a bad ink sensor board -- leaking ink sometimes contaminates the board -- or the board may be off its mounts. I suggest you bring your unit to service center and have your sensor checjed/diagnosed.
- In rapid succession, touch Menu, Black-Start, ^, ^, ^, ^. (That's the up-arrow button, four times.)
- If you were successful the display should read MAINTENANCE, and all lights should flash together. If not, touch STOP and try it again.
- Touch 9, 1. The display should read PARAM INIT for a few seconds, while it erases most of its memory. It will not clear its programmed name and phone number, nor the fax directory entries.
- Touch 9, 9 to exit Maintenance Mode. The machine will go through its complete power-up sequence, taking about a minute to reach its Ready condition.
- A more desperate step would be to repeat this sequence, except instead of touching 9,1 touch 0,1. This will clear ALL memory, including all programmed names and phone numbers, bringing it back to new, out-of-the-box condition.