Technical information

2.3.2.1 Function Checks
Basic functions may be checked using the self-test raster.
Refer to "Adjustment Procedures" in topic 2.3.2.3 when adjustments are
required.
Refer to "Display-Specific Removals and Replacements" in topic 2.3.1 for
removal and replacement procedures.
+------------------------------------------------------------------------+
¦ Symptom ¦ Action ¦
+-----------------------+------------------------------------------------¦
¦ Any problems. ¦ First, check all connections and associated ¦
¦ ¦ items for continuity. ¦
+-----------------------+------------------------------------------------¦
¦ Green LED lit but ¦ Check CRT heater. If not glowing, replace card ¦
¦ test raster missing. ¦ assembly. Otherwise, adjust G2 control ¦
¦ ¦ clockwise until test raster appears AGAINST ¦
¦ ¦ background raster. If no raster appears ¦
¦ ¦ replace ITC. ¦
+-----------------------+------------------------------------------------¦
¦ One or more colors ¦ Adjust cut-off controls for missing colors. If ¦
¦ missing from ¦ colors reappear, reset color-point of ITC. ¦
¦ background raster. ¦ Otherwise replace ITC. ¦
+-----------------------+------------------------------------------------¦
¦ One or more colors ¦ Adjust gain controls for missing colors. If ¦
¦ missing from test ¦ colors reappear, reset color-point of ITC. ¦
¦ raster. ¦ Otherwise replace ITC. ¦
+-----------------------+------------------------------------------------¦
¦ Test raster scan is ¦ If partially collapsed, adjust as appropriate. ¦
¦ collapsed ¦ If fully collapsed, replace card assembly. ¦
¦ horizontally/ ¦ ¦
¦ vertically. ¦ ¦
+------------------------------------------------------------------------+
PS/2 Displays Maintenance Manual
Function Checks
¦ Copyright IBM Corp. 1993
2.3.2.1 - 1