Hvps (Bias Transfer Roll -) Operation - Olivetti DR N17 Service Manual

5.2.1.25 HVPS (Bias Transfer Roll -) Operation

This diagnostic tests HVPS negative DC voltage to the Bias Transfer Roll.
WARNING! This test switches on the HVPS. Never touch the parts supplied with a high voltage
from the HVPS when running the following diagnostics. The HVPS output voltages
switched on by these procedures can be measured by means of a multimeter. Be
sure to observe the following procedures to check the voltages.
1 Enter Diagnostics Mode 1. The LCD displays PRINT COUNTER OPERATION indicating the
printer is in Diagnostics Mode 1.
2 Press the MENU UP (1) or MENU DOWN (5) key until the LCD displays HVPS (T. ROLL- )
OPERATION message.
3 Remove the EP Cartridge from the printer.
4 Bypass the Front Cover interlock switch and the EP Cartridge interlock switch with an Interlock
Bypass key or equivalent.
5 Set the multimeter to read a momentary minus DC voltage (approximately one second in
duration), in the 1000 VDC range.
6 Connect the multimeter to the following terminals:
• Positive test probe directly to the shaft of the Bias Transfer Roll
• Negative test probe to the LVPS frame or the printer frame.
7 Press the ENTER key to execute the test. The LCD displays the HVPS (T. ROLL- ) message.
HVPS (T. ROLL- )
Operation EXECED
NOTE: Voltage is present for approximately one second each time the ENTER key is pressed.
8 The normal momentary HVPS Bias Transfer Roll output voltage is approximately -900 VDC.
9 If you wish to exit this test and enter another test use the MENU UP (1) or MENU DOWN (5) key
to scroll to another test.
10 To exit this test and return to normal operation, switch the printer power OFF and then switch it
ON.
687200Q Service Manual 5-55