IBM 3112, Service Manual

Page: 48 / 184

bh1s.bk : bh1sdiag.doc 32 Thu Apr 20 12:42:16 1995
32
Service Manual
If the test print frame is not parallel to the left and right edges of the
paper, the paper has skewed in the paper path. Check the paper path
for obstructions. Make sure the paper in the tray is loaded properly and
is undamaged. Check the prealigner, drive, and auxiliary rollers,
springs, and backup rollers for dirt, wear, or damage; refer to the parts
catalog for repair kits for broken bellcrank spring attachment hooks on
the sideframe. Make sure all the bellcrank assemblies pivot freely.
Check the gear train for damage or binds.
Skew, top and bottom only
If the test print frame is parallel to the left and right edges of the paper
but not parallel to the top and bottom, the printhead skew needs to be
adjusted.
See
“Printhead Skew” on page 61.
Stalled (diamonds on display)
Check the continuity of the cable from J1 on the engine board to the
operator panel. Next reseat the ROM and memory SIMMs and POR.
This condition can also occur if the RIP and engine board are not
seated or their connectors are damaged.
If the problem is still present, replace one at a time the:
1. ROM SIMM
2. Engine board
3. RIP Board