NEC LCD1550X Service Manual page 33

SEE USER'S MANUAL FOR
MORE INFORMATION
Key operations:
: Selects an item (downward). (Moves upward when at last line)
: Selects an item (upward). (Moves downward when at top line)
+ : Invalid
- : Invalid
NEXT : Invalid
RESET : Invalid
EXIT : Exits the OSM menu
The DVI SELECT menu for the OSM function is shown above. The DVI-I DDC is changed on
this screen. The Ch is saved in the initialization EEPROM (IC100) when selected, and the
EEPROM (IC104 or IC105) in which the EDID data (for analog/digital) to be selected is stored
can be accessed. When DIGITAL is selected, the DVI-I (D) EDID data will be read in immedi-
ately after selection, and when ANALOG is selected, the DVI-I (A) EDID data will be read in.
The above OSM menu will open when "-" or "+" is pressed while the DVI "NO SIGNAL" or "OUT
OF RANGE" is displayed for OSM, and the current setting state can be confirmed. In addition,
if the setting value does not match the PC and is not displayed on the screen, the problem can
be resolved by displaying this OSM menu and changing DDC. The DDC switching circuit is
compatible with the asset management function, and the changed settings are saved even
when the monitor power is OFF. Thus, the selected EDID data is read in.
When considering the asset management function, the external power (+5V) supplied from the
signal connector may be lower than the Standards depending on the PC. (The power is 5V±5%
for VESA Standards.) As a design margin, the power should be 3V at the signal connector, and
at least 2.7V at the V
Thus, the DDC peripheral circuit uses an IC having a V
voltage. V : 2.5V (Min.) EEPROM is used to provide a margin. Note that it is 5V±5% for the
CC
specifcation of this LCD monitor.
of the DDC peripheral circuit IC after passing through the shot diode.
CC
that operates at a 2.7V to 5.5V power
CC
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