HP LaserJet II Serie Manual De Instrucciones página 239

HP 33440/HP 33449 COMBINED SERVICE MANUAL
Light Blocking
Shutter 1
(Laser Opening),
~
Sensitivity
/
Tabs
\ ((\G
Shutter Tabs
Primary Corona
(Behind Cover)
Figure 7-29. EP-S cartridge {End
view)
Primary Corona Functional Check
Veri& that the Primary Corona (HV1ON) enable signal on the High-Voltage Power Supply
Assembly is functioning as follows
1. Using a voltmeter and frame ground as a reference, measure the voltige level at J21O-8 (Test
Connedor, see Figure 7-30) on the DC Controller PCA while performing a Test Print. The
voltige level should switch betieen + 18.0 Vdc (disabled state) and 0.0 Vdc (enabled state) one
second after the print cycle begins. If the voltage at J21O-8 does not switih, replace the DC
Controller PCA. If the signal line is being switched but the Primary Corona does not appear
to be functioning (i.e., producing black pages), replaw the EP-S Cartridge followed by the
High-Voltage Power Supply Assembly.
Developer AC Bias Functional Check
Verify that the Developer AC Bias (DBAC) enable signal on the High-Voltige Power Supply
Assembly is functioning as follows:
1. Using a voltmeter and frame ground as a reference, measure the voltage level at J21O-6 (Test
Connector, see Figure 7-30) on the DC Controller PCA while performing a Test Print. The
voltage level should switch between +18.0 Vdc (disabled state) and 0.0 Vdc (enabled state) three
seconds after the print ~cle begins. If the voltige at J21O-6 does not switch, replace the DC
Controller PCA. If the signal line is being switched but the developer AC bias does not appear
to be functioning (i.e., producing very faint print), replace the EP-S Cartridge followed by the
High-Voltage Power Supply Assembly.
Note The absence of the Developer AC Bias will dso result in a perpetual 16 TONER
LOW condition.
7-75