Continuous alternating fast flashing lights appear when the unit is powered on.
You may have a defective cartridge. Try the following:
1. Remove both the color and the black cartridge.
2. Power off the unit.
3. Power on the unit with no cartridges installed.
4. The unit should initialize by displaying the continuous alternating fast flashing lights for only 30 seconds. If the unit initializes correctly try replacing the original cartridges using the procedure outlined in your manual for cartridge replacement.
5. If the unit now functions correctly, the cartridges are not defective and the problem was caused by a temporary connection loss that should not reappear.
6. If the problem continues, either the color or the black cartridge is defective. Try replacing one or both and restart the unit. (The defective cartridge is most likely the one that was most recently replaced.)
Note: If nothing here solves the problem try pressing the ink button during the light sequence. If the lights stop flashing, attempt to update the firmware at this time. If the firmware update is successful, the problem will be solved.