High Voltage Data Error Detection; Beam Current Protector; Power-On Indicator (Led) Flickering Pattern In Each Protector Operating; Operating Time - NEC DPro2070SB Service Manual

1.6.6.2 High voltage data error detection

Important safety data, such as the high voltage adjustment value and the X-ray protector activation
voltage, are stored in the EEPROM. For each safety data, there is backup data. If both data values differ
from each other, the monitor will enter the power saving mode (the high voltage will not be applied).

1.6.6.3 Beam current protector

If too much beam current flows (1.5mA or more), "H" will be input to the ABL terminal (pin 27 of the
microcomputer (IC102)). From this terminal, the microcomputer will detect overflow of the beam current,
and will set the monitor in the power saving mode.

1.6.6.4 Power-On Indicator (LED) flickering pattern in each protector operating

If a protector is activated, the Power-On Indicator (LED) will flicker as shown below to indicate the
activated protector (to show the cause of the problem).
Table 2 Power-On Indicator (LED) flickering pattern in each protector operating
Protector state
X-ray protector
High voltage circuit latch
detection
Data protector
Beam protector
+B short-circuit

1.6.6.5 Operating time

If "DIAGNOSIS" is selected from the menu in the factory mode, the monitor operation time will appear. 0.5
hours will be added to this value every 30 minutes.
P: Indicates the power-on time (including the operation time in the power saving mode).
K: Indicates the heater power-on time.

1.6.6.6 The DDC communication

The microcomputer carries out the DDC communication. For this communication, the microcomputer
reads out the EDID data from the EEPROM, and stores the data in the RAM. When receiving a request
from the PC, the microcomputer will output the data from pins 8 and 11.
Power-On Indicator (LED) state
Short (0.5s) lighting times
1
2
3
5
7
1- 21
Long (2s) lighting times
1
1
1
1
1