Konica Minolta bizhub C658 Service Manual page 1894

bizhub C658/C558/C458/C368/C308/C258
Fault name Mode
Standby
High All modes
temperature 2
(2) Abnormal power supply input detection
• The IH power supply unit reduces power to the IH coil when the voltage input into the IH power supply has decreased. When capacity of
fusing cannot be maintained due to reduced IH coil power, PPM control is implemented to reduce print productivity from 100% to 40% in
stages.
• The IH power supply unit displays a trouble code when the input power or voltage values are abnormal.
Fault name
Input power Input current or power has exceeded the upper
abnormal limit value.
Input current or power has fallen below the
lower limit value.
Input voltage The input voltage has exceeded the upper limit
abnormal value.
The input voltage has fallen below the lower limit
value.
14.3.11 Temperature sensor control
• A non-contact type thermopile sensor is used for heating roller temperature sensor (hereinafter referred to as "temperature sensor"). The
temperature sensor detects the temperature of the fusing belt through infrared rays and controls the surface temperature.
• The temperature sensor is provided with a lens. For its structural reason, therefore, the temperature sensor can be dirtied by dew
condensation formed or foreign matter deposited on the lens.
• The temperature sensor, if contaminated with dew drops or dirt on the lens, becomes unable to detect the temperature accurately, since
the contaminants blocks the infrared rays that are otherwise detected by the sensor.
• If temperature control is provided under such conditions, the temperature sensor detects a temperature that is lower than the actual
temperature of the fusing belt. Then, the fusing belt temperature is controlled based on a temperature higher than the target one.
(1) Detection of condensation on the heating roller temperature sensor
• The control of detection of condensation on the heating roller temperature sensor is to determine degradation of detection accuracy of
the temperature sensor caused by condensation or dirt.
• When the difference in temperature between that detected by heating roller thermistor3 and that detected by heating roller temperature
sensor is equal to, or more than, a specified value and that condition lasts for predetermined period of time or more, the machine
determines that the heating roller temperature sensor lens has condensation on it.
• When condensation on the temperature sensor is detected and the control is switched to "alternative temperature control", the machine
displays the corresponding P code "P-32 Heating roller temperature sensor temperature detection failure" on the control panel.
(2) Detection of contamination on the heating roller temperature sensor
• The contamination detection control is to determine degradation of detection accuracy of the heating roller temperature sensor caused by
contamination.
• The contamination detection control is performed only in the standby state. No control is provided during the alternative temperature
control initiated by condensation of the temperature sensor.
• If contamination of the lens of the heating roller temperature sensor is detected, the machine displays the corresponding malfunction
code "C-392A heating roller temperature sensor contamination (Main of the heating roller)" on the control panel. It then shuts down the
circuit to the main coil and terminates fusing unit temperature control.
• If, after the start of the contamination detection control, the difference in temperature between that detected by heating roller thermistor3
and that detected by heating roller temperature sensor is equal to, or more than, a specified value and that condition lasts for 10 min. or
more, the machine determines that the heating roller temperature sensor lens is contaminated.
• The contamination detection control is terminated if, at any timing within 10 min. after the contamination detection control has been
started, the difference in temperature between that detected by heating roller thermistor/1 and that detected by heating roller temperature
sensor is equal to, or less than, a specified value.
• The contamination detection control is terminated if the machine enters any mode other than the current one, including the warm-up or
the low power mode as initiated by the start of a print cycle or restart.
(3) Heating roller alternative temperature control
• If condensation on the heating roller temperature sensor is detected, the heating roller temperature control is provided based on the
temperature detected by the heating roller thermistor3, instead of that detected by the heating roller temperature sensor. This control is
referred to as the heating roller alternative temperature control.
• When the control is switched to the alternative temperature control, the machine displays the corresponding P code "P-32 Heating roller
temperature sensor temperature detection failure" on the control panel.
• If the difference in temperature between that detected by heating roller thermistor3 and that detected by heating roller temperature
sensor becomes less than a specified value during the alternative temperature control, the machine determines that condensation on the
heating roller temperature sensor has been eliminated and resumes the temperature control based on the temperature detected by the
heating roller temperature sensor.
• If the difference in temperature between that detected by heating roller thermistor3 and that detected by heating roller temperature
sensor is not improved even after the lapse of 10 min. after the alternative temperature control has been initiated, the machine
determines that the cause is not condensation, but contamination, on the lens and terminates the alternative temperature control.
Control contents
The rotation speed of the IH power supply cooling fan is
increased from 50% to 100%.
The speed returns to 50% when a temperature of 90 degree is
detected for at least 30 seconds.
A trouble code appears.
Detection method
O THEORY OF OPERATION bizhub C658/C558/C458/C368/C308/C258 > 14.
Control contents
A trouble code appears.
A trouble code appears.
O-119
FUSING SECTION (bizhub C658/C558)
Code
C3B02 IH malfunction (CPU)
Code
C3B07 IH input power error
C3B08 IH input voltage
error