When you turn on power, expect the following events. If the printer fails any portion of this sequence, it displays the message "Self Test Error."

The boxes on the left indicate the primary responsible controller PCB: "EC"stands for the engine controller PCB and "RIP"stands for raster image processor PCB.

Engine Controller	Raster Image Processor	Action
X		Fans operate.
X		The printer sounds out two short and one long beep if printer memory and firmware are okay. If not okay, the printer displays the message "Self Test Error". The printer may sound out a series of cascading up/down tones which indicate a memory error. Note: Cascading tones will occur with checksum errors following firmware replacement. In those cases, press ON LINE or cycle power off and on again. If necessary, call for service
X		The printer checks that the top cover is closed.
	X	The printer lights the READY and ON LINE lights.
X		The printer checks for paper, paper jam, drum, waste toner bottle. If item is missing or if paper is jammed, the printer sounds out three short beeps and then displays "Load Paper", "Paper Jam", "Need Print Drum", or "Need Toner Cup".
X		Next, the printer turns on the main drive motor. You hear the sound of a motor and its gears as the printer prepares the developer and drum.
X		The printer checks out the erase lamps in the top cover. The heat lamp in the fuser is turned on.
X		Toner is checked. If low, the printer reports "Toner Low".
X		The laser scan unit (LSU) is checked. If not functioning properly, the printer reports "Laser Failure".
X		If the fuser fails to reach the preset fuser temperature in two minutes from being turned on, the printer displays the message "Fuser Failure".
	X	The printer waits for the first print job from the host.