Pre-Transfer Corona - Ricoh FT7060 Field Service Manual

12 July '86

61. Pre-transfer Corona

OPTIMUM VALUE: PTC ac = 42.4 to 42.7A
1. Position the drum shoe [A] in the center and align it with the pre-
transfer corona unit [B] as shown.
2. Select the ac µA range on the digital multimeter.
range of the digital multimeter, make sure the copier's main switch is
off.)
3. Turn on the main switch and the PTC corona using SP 11-3.
4. Adjust the PTC corona ac current by turning VR "AC" [C] on the PTC
power pack.
5. Turn off the copier's main switch and select the dc µA range on the
digital multimeter.
6. Turn on the main switch and the PTC corona.
7. Adjust the PTC corona dc current by turning VR "DC" [D]. (Let the
reading stabilize for 10 seconds.)
adjust the dc current. It is usually necessary to repeat this adjustment
two or three times, because adjustment of the dc current will cause a
slight change in the ac
8. Remove the drum shoe,
dc = -28.6 to -28.8A
(Let the reading stabilize for 10 seconds.)
current and vice versa.
reinstall all parts, and check copy quality.
Adjust the ac current first and then
3-82
(When changing the