Ricoh G035 Service Manual page 72

DRUM CHARGE
If the humidity drops, the drum potential goes up even if the voltage supply for the
charge roller remains the same (efficiency of voltage transfer decreases with
increased humidity). As a result, more toner is transferred to the ID sensor pattern
[B]. If the sensor output reaches a certain point, the drum charge voltage is
reduced.
To determine whether to change the drum charge roller voltage, the machine
compares Vsdp with Vsg.
• Vsdp/Vsg > 0.90 = Reduce the drum charge voltage by 30 V
• Vsdp/Vsg < 0.85 = Increase the drum charge voltage by 30 V
NOTE: The minimum drum charge roller voltage is –2 kV.
Correction for Paper Width and Thickness (By-pass Tray Only)
The by-pass tray can feed narrow, thick and special paper types (OHPs) that the
standard tray can not. If you use the standard tray with these special paper types,
some print quality problems may occur.
To deal with this, the charge roller receives a higher voltage for when using paper
fed from the by-pass tray. Adjust the voltage with SP2-13-1 and 2. Charge roller
input voltages
Paper width from 216 mm to 297 mm: SP2-5-1
Paper width from 150 mm to 216 mm: SP2-5-1 + 50 V (adj. with SP2-13-2)
Paper width below 150 mm: SP2-5-1 + 250 V (adj. with SP2-13-1)
Similar voltage adjustments are available for development bias and transfer
current.
G035 2-20 SM