A
PPENDIX
B, F
IELD
S
ERVICE
M
ENU
44
PRELIMINAR
Y
changes. The technician has the only possibility to change the original EEPROM Sensor Calibration
and Convergence coordinates by storing any new coordinates into the default EEPROM using
“Defaults” in the Autoconvergence menu.
Convergence
Micro
DEFAULT
EEPROM
2H
EEPROM
2.14H
EEPROM
Store
Defaults
Store 2H
Offsets
Store 2.14H
Offsets
Offsets stored automatically
after each Sensor Calibration
and Auto-convergence
New defaults, over-riding
original factory defaults
may only be stored by Technician
via Chipper Check or Field
Service Menu
Default Sensor Calibration locations
and Convergence points stored at
the time of manufacture
C
ONVERGENCE
C
IRCUIT
O
PERATION
The convergence circuitry must be understood in order to prevent errors in procedures. The
convergence microprocessor directs all convergence operation independently of the main chassis
microprocessor. Geometry is independent of convergence except for modifications to geometry
done during the “Sensor Calibration” routine.
Of great importance is understanding where convergence alignments are stored and how they are
dealt with during different operations. The Default EEPROM holds the convergence alignment
values used during any autoconvergence procedure. The 2H and 2.14H Mode EEPROMs contain
only the differences between the Default EEPROM values and the values found by the
autoconvergence routine representing current ideal convergence. So during a 2H autoconvergence
attempt if the Default EEPROM says a specific alignment point should be at +155, +20 yet
autoconvergence locates it at +160, +15, the 2H EEPROM for that location will be +5, -5. The
same is true for all 195 alignment points for all three colors. The Default EEPROM values will
not change unless the technician changes them using the “Store Defaults” routines.
During the final convergence of the instrument at manufacturing all convergence alignments, both
2H and 2.14H, are stored into the “Default” EEPROM. Since at this time the “Default” values are
identical to the current autoconvergence values the offset values held in the 2H and 2.14H EEPROMs
are null.
When autoconvergence runs there are typically many of the convergence points that have changed
from the original manufacturing setup due to environmental conditions. The original manufacturing
values are not changed. All changes are stored in the 2H (or 2.14H depending upon the mode)
EEPROM so that the original alignment values are always available by accessing the Default
EEPROM.
