Olivetti d-color MF651, Service Manual, Page: 787 / 1053

Field Service Ver. 2.0 Jul. 2009 19. TROUBLE CODE
727
TROUBLESHOOTING
C2354 Rear side cooling fan
motor’s failure to turn
• The motor lock signal remains HIGH for a
predetermined continuous period of time
while the motor is turning.

B
C2551 Abnormally low toner
density detected cyan
TCR sensor
• When sampling data is determined in TC
ratio calculation control, TCR sensor output
is higher than a predetermined value for a
predetermined number of times in a row
even though there is toner in the sub hop-
per.
 B
C2552 Abnormally high toner
density detected cyan
TCR sensor
• TC ratio in the developing unit which is
determined by Toner replenishing amount
control mechanism, is a predetermined
value or more for a given number of times
consecutively.
 B
C2553 Abnormally low toner
density detected magenta
TCR sensor
• When sampling data is determined in TC
ratio calculation control, TCR sensor output
is higher than a predetermined value for a
predetermined number of times in a row
even though there is toner in the sub hop-
per.
 B
C2554 Abnormally high toner
density detected magenta
TCR sensor
• TC ratio in the developing unit, which is
determined by toner replenishing amount
control mechanism, is a predetermined
value or more for a given number of times
consecutively.
 B
C2555 Abnormally low toner
density detected yellow
TCR sensor
• When sampling data is determined in TC
ratio calculation control, TCR sensor output
is higher than a predetermined value for a
predetermined number of times in a row
even though there is toner in the sub hop-
per.

B
C2556 Abnormally high toner
density detected yellow
TCR sensor
• TC ratio in the developing unit, which is
determined by toner replenishing amount
control mechanism, is a predetermined
value or more for a given number of times
consecutively.

B
C2557 Abnormally low toner
density detected black
TCR sensor
• When sampling data is determined in TC
ratio calculation control, TCR sensor output
is higher than a predetermined value for a
predetermined number of times in a row
even though there is toner in the sub hop-
per.

B
C2558 Abnormally high toner
density detected black
TCR sensor
• TC ratio in the developing unit, which is
determined by toner replenishing amount
control mechanism, is a predetermined
value or more for a given number of times
consecutively.

B
Code Item Detection timing
Trouble iso-
lation
Rank
Y110571-1 Service Manual