Kyocera KM-4230 Service Manual page 57

2A3/4
Toner level detection
The toner level in the toner main hopper is monitored by the toner level detection sensor
(TLDS). It converts the presence or absence of toner in the toner main hopper into a
voltage and sends it to the main PCB (MPCB), which triggers a message to request the
toner cartridge to be replaced before the recycled toner ratio in the toner main hopper
reaches a significant level.
Toner feed motor (TFM)
4.5 V
Toner level detection
sensor output voltage
0.5 V
A When the toner level detection sensor (TLDS) output voltage drops below 0.5 V while
the toner feed motor (TFM) is on, the toner motor drive time starts to be counted.
B If the toner level detection sensor (TLDS) output voltage remains below 0.5 V for 10 s,
the toner request message appears.
Note: When the toner request message is displayed under these conditions, the
available copy mode and the number of copies that can be made are
restricted as set in maintenance item U258 (see page 3-2-74).
C Toner empty detection is ignored for 1 min. (the toner feed motor on time) after the toner
cartridge has been replaced. If the toner level detection sensor (TLDS) output remains
at 4.5 V or above for 10 s, toner empty detection is reactivated.
D Toner empty detection is ignored for 5 min. (the toner feed motor on time) after
maintenance item U130 has been performed for developer initial setting. If the toner level
detection sensor (TLDS) output remains at 4.5 V or above for 10 s, toner empty detection
is reactivated.
1-3-34
Toner request message Toner empty detection
Toner cartridge to be
replaced.
Toner empty detection
TFM: on ignored.
10 s
A B
Figure 1-3-31 Toner level detection
reactivated.
U 130 performed.
Toner empty
detection ignored.
1 min. 5 min.
10 s
C
Toner empty detection
reactivated.
10 s
D