Panasonic UF-490 Service Manual page 135

Laser Unit (LSU) Error Detection
nSTART
(CN10, 3)
Polygon Motor ON
nREADY
(CN10, 2)
Polygon Motor Ready
E054
nREADY
Polygon Motor does not
reach constant speed
during wake up state.
E054
nREADY
Polygon Motor does not
maintain constant speed.
nLDEN
(CN10, 9)
Laser Enable Signal
nVIDEO
(CN10, 8)
Laser Timing Signal
nHSYNC
(CN10, 13)
Laser Timing Detection
E054
nHSYNC
(CN10, 13)
Can not detect
Laser Timing
Motor ON 5 sec
nREADY does not go low for more than 2 sec during 3 sec to
20 sec after nSTART goes low.
nSTART nREADY:ON
nREADY goes high 4 times during printing.
1.23 ms (600 x 600dpi)
nHSYNC timing signal is less than 60% of Normal Condition
135
Normal Condition
20 sec
OFF OFF
1.89 ms (16 x15.4 line/mm)
Normal Condition
OFF OFF