IBM 3112, Service Manual

Page: 31 / 184

bh1s.bk : bh1sdiag.doc 15 Thu Apr 20 12:42:16 1995
Diagnostic Information
15
voltages; then stop the test and check the voltages again:
If any voltages are not correct replace the engine board.
If no problem is found, enter the diagnostics mode and change the
Charge Roll setting.
Users who run large jobs with very dense graphics in high humidity
environments may get some print quality improvement from increasing
the Transfer setting; users with more normal jobs will see no difference.
Make sure the HVPS contacts to the transfer roll housing are in good
condition.
Black Page
Black output is usually caused by an incorrect high voltage in the print-
ing process, resulting in toner development on the entire photoconduc-
tor drum. Check the condition of each HVPS contact and make sure
they spring back when pressed. Check the continuity of the HVPS
cable. Make sure the following voltages are correct; if they are not,
replace the engine board.
Run the Print Test with the RIP Board removed. Make the following volt-
age checks while printing and again while idling. If the voltages are not
Connector
Voltage while
Printing
Voltage while Idling
J13-1 Less than 5VDC 0VDC
J13-2 Less than 5VDC 0VDC
J13-3 (Fluctuates
between pages)
+1.5VDC 0VDC
J13-8 Less than 1VDC +6VDC
Connector Voltage
J13-5 to J13-4 +24VDC
J13-6 to J13-4 +24VDC