The LaserWriter Select 310 and 360, and the Personal LaserWriter 320 go through a self diagnostic each time you switch the printer on. This diagnostic is called the Power-On Self Test (POST). Observing how the LEDs extinguish from that point can help isolate certain failure areas.
NOTE: This test is not the same as the engine diagnostic. Unlike the
engine diagnostic test, POST does not require the placement of any
loopback cable.
NOTE: POST does not occur on the LaserWriter Select 300 or the Personal
LaserWriter 300 printer.
1) When you switch on a functional printer, all LEDs will illuminate for a
short time.
2) The Ready LED extinguishes when no errors are found on the I/O
controller board.
3) Then the Paper-Out LED extinguishes when no errors are found on the RAM
card.
4) Finally the Jam LED extinguishes when no errors are found in the engine.
NOTE: In a functional printer, control will be passed on to the PostScript
interpreter at the end of this sequence.
Article Change History:
17 May 1996 - Added LaserWriter Select 310 back into article.
27 Apr 1996 - Removed references to LaserWriter Select 310.