IBM 3112, Service Manual

Page: 57 / 184

bh1s.bk : bh1saids.doc 41 Thu Apr 20 12:42:16 1995
Diagnostic Aids
41
Duplex Feed 1 Test
This test checks for slipping paper problems. It verifies that the
paper is entering the duplex unit far enough for the trailing edge to
clear the selector fingers before the paper reverses direction.
1. Enter Diagnostics mode.
2. Select [DUPLEX TESTS].
3. Select [Duplex Feed 1].
4. Select [Tray 1], or [Tray 2].
Note: Paper feeds all the way into the duplex unit and stop.
5. The message [Clear Paper] appears on the display.
6. Slide the tray extension all the way out until it stops.
7. Push a small screwdriver through the lower end of one of the
ventilation slots and through the sheet of paper fed in under the
slot.
8. Open the cover and remove the sheet of paper.
9. Measure the distance from the mark on the paper to the trailing
edge of the paper. If the mark, or hole, is more than 85 mm from
the trailing edge, there is a paper slipping problem with the
duplex unit paper feed.
Duplex Feed 2 Test
This test verifies that paper feeds through the duplex unit properly
and tests the stop point of the page as it feeds back over the top of
the duplex paper tray.
1. Enter Diagnostics mode.
2. Select [DUPLEX TESTS].
3. Select [Duplex Feed 2].
4. Select [Tray 1] or [Tray 2].
Note: Paper feeds all the way into the duplex unit and then
feeds out and stops on top of the paper tray.
5. The message [Clear Paper] appears on the display.
6. Open the printer top cover.
7. If you are doing the test with legal size paper, open the top cover
of the duplex unit.