Ricoh FT4227 Manual page 321

TONER SUPPLY 12 February 1992
After the second check if the ID sensor data is still at the toner end level on
every check, the toner supply ratio increases by 1 step until it reaches the
maximum toner supply ratio (60%: black, 28%: color).
If the CPU detects the toner end level twice at maximum toner supply ratio,
the Add Toner indicator starts blinking.
50 more black copies (or 10 more color copies) can be made before the "Add
Toner" indicator turns on continuously and the Start key turns red.
If the main switch is turned off and on while "Add Toner" is indicated (blinking
or lighting) the main motor starts turning and toner is supplied for about 10
seconds.
After 10 seconds an ID sensor pattern is made 4 times.
If the average of the ID sensor data is in the toner end range , the Add Toner
indicator turns on continuously and the start key turns red.
Opening and closing the front door is the same as turning the main switch off
and on.
These main switch and front door operations are for black toner mode only.
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