Epson AcuLaser C1900 Reference Manual page 298

Check Media Type
You have loaded media other than transparencies when the Paper
Type setting in the printer driver is Transparency. The printer
stops loading to prevent printer damage. Load transparencies in
the specified paper source, then press the Start/Stop button.
Clean Sensor
The sensor inside the printer is dirty. Open and close the front
cover. Automatic cleaning is performed.
Collate disabled
Printing by specifying the number of copies is no longer possible
due to a lack of memory (RAM) or free disk space on the optional
Hard Disk Drive. If this error occurs, print only one copy at a time.
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.
Cooling Down
The printer lowers its temperature to optimize for the fixing toner.
Wait for a moment for Ready to appear in the LCD panel.
Cover C Open
Cover C of the optional 500-Sheet Paper Cassette Unit is open.
Close the cover.
Duplex Mem Overflow
There is not enough memory for duplex printing. The printer
prints only on the front and ejects the paper. To clear this error,
follow the instructions below.
298
Troubleshooting