Dell P1500 Personal Mono Laser Printer - Manual (Page 63)

The printer has a service error and printing has stopped.
What you can do:
Turn the printer off and back on. If the lights are still blinking, contact Dell.
Secondary error code
What this light sequence means:
The printer has one of the following errors:
Memory is full.
A page is too complex to print.
A page is shorter than the set page margins.
Resolution of a formatted page is reduced to 300 dpi before printing.
A font error occurred.
Memory is insufficient to save what is in the buffer.
Printer memory is insufficient to defragment flash memory.
Communication with the host computer is lost.
What you can do:
Press and release Continue twice quickly to see the secondary
message.
Press and release Continue to clear the secondary message.