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Troubleshooting
●
No Power
This LCD Projection Monitor provides a function which can be specified a defective area simply by indicating the LEDs
on the control panel. Connect the AC cord and press the Power button once and then check the LED indication.
- When the WARNING(red) and POWER(red) indicators are flashing,
the symptom indicates that the LCD
Projection Monitor detected an abnormal temperature risen inside the LCD Projection Monitor. Check the air fil-
ters and wait until the POWER indicator stops flashing, and then try to turn on the LCD Projection Monitor.
The internal temperature is monitored by sensor ICs, IC8861 on Sensor Board, IC8801 on Main Board.
Reset switch
The microprocessor inside the
LCD Projection Monitor may occa-
sionally malfunction and does not
allow any controls. In this case,
press the reset switch on the rear
panel with a sharp tool to restart
the LCD Projection Monitor.
POWER
ONTIMER
INPUT
VIDEO3
VIDEO/Y — Pb/Cb — Pr/Cr
L—AUDIO—R
(MONO)
RESET
Lamp cover switch
Make sure that the lamp cover
is mounted correctly. If not or
the lamp cover removed, the
lamp does not light on for the
safety. Check the lamp cover
and lamp cover switch
(SW1861).
- When all the LED indicators are not lighting,
the symptom indicates that the primary power supply circuit
does not operate properly. Check the power primary circuit and parts as follow;
AC cord
F601 (Fuse)
Power board
SW902 (Thermal sw.) ......short in normal
SW902 opens when the surrounding temperature of the switch exceeds 80°C.
- When the WARNING (red) indicator lights
, the symptom indicates that the LCD Projection Monitor detected
an abnormality in the cooling fan operation or in the power supply secondary circuits. Check fan operation and
power supply lines, and the driving signal status.
An abnormality occurs on the secondary power supply lines.
Power failure detection diodes detect abnormal voltage on the power supply circuits.
POWER_FAIL (Error:L) signal is sent to pin 174 of IC301(Main CPU) via IC851(Comparator), and then
FAN_SW signal from IC301 is sent to the Power board and the LCD Projection Monitor is shut down.
Check the shortage of secondary circuits, ICs, condensers, etc.
Check power supply lines, 15V, 5V, 3.3V and 1.5V on the Main Board.
An abnormality occurs on the fan control circuits.
Power failure detection diodes detect the fan operation stop. Check FN901, FN902, FN903, FN904 and
peripheral circuit.
Check fan's power supply lines and detection diodes D7807, D7827 and D7847.
Check fan lock signal(Lock:H) and Q7891, IC1811 and peripheral circuit.
An abnormality occurs on power starter signals (FAN_SW, 5V_SW).
FAN_SW signal (Power-on:H) is output from pin 19 of IC1802 and applied to the Sub-power Board. It drives
the power oscillation circuit and power supply for the cooling fans in Sub-power Board.
5V_SW signal(Power-on:H, stand-by:L) is output from pin 18 of IC1802 for SW-On/Stand-by.
An abnormality occurs on Lamp drive signal (LAMP_POW, LAMP_ERR).
- LAMP_POW signal(Power-on:H) is output from pin 14 of IC1803 and sent to IC1861 via IC1891.
LAMP_ON signal(Lamp-on:H) is output from pin 12 of IC1871 and sent to Lamp Ballast Unit through
SW1861(Lamp Cover SW).
- Tx_LAMP signal is output from pin 3 of IC1861 and sent to Lamp ballast Unit via IC1871.
- Rx_LAMP signal(Lamp status signal) is output from the lamp ballast unit and sent to pin 4 of IC1861 via
IC1871, then LAMP_ERR signal is output from pin 7 of IC1861 and sent to IC301 via IC1811.
If an abnormality occurred on the lamp ballast unit, Rx_LAMP signal and LAMP_ERR signal become "H"
and then IC301 shuts down the power supply circuit.
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