Epson AcuLaser C1900 Reference Manual page 300

Hard Disk Full
The printer has insufficient memory. Delete the unnecessary data
from the Hard Disk Drive.
To clear this error, select Clear Warning from the control panel's
Reset Menu. See "How to access the control panel menus" on page
199 for instructions.
HDD Check
The printer is checking the Hard Disk Drive.
Image Optimum
There is insufficient memory to print the page at the specified
print quality. The printer automatically lowers the print quality
so that it can continue printing. If the quality of the printout is not
acceptable, try simplifying the page by limiting the number of
graphics or reducing the number and size of fonts.
To clear this error, select Clear Warning from the control panel's
Reset Menu. See "How to access the control panel menus" on page
199 for instructions.
Turn the Image Optimum setting off on the control panel's Printing
Menu if you do not want the printer to automatically lower the
print quality to continue printing.
You may need to increase the amount of printer memory to be
able to print at the desired print quality for your document. For
more information on adding memory, see "Memory module" on
page 324.
Install Photocondctr
There is no photoconductor unit installed or the photoconductor
unit is not installed properly. Install the photoconductor unit if it
is not installed.
300
Troubleshooting