Self Diagnosis Circuit (A Board) - Sony KL-X9200M Service Manual

1-5. SELF DIAGNOSIS CIRCUIT
(A BOARD)
IC1
SYSTEM CONTROL
SDAT1 96
SCLK1
98
I LAMP PROT 77
I FAN PROT
79
(TB BOARD)
I FILT COV 81
(TA BOARD)
I LAMP COV
82
O POW CTL 54
5V
I 5V
67
I LAMP DRV
78
POWER LAMP
LED LED
HB
D1874 D1871 D1873
SCL1,SDA1
(LAMP PROT)
PROT LAMP
D2020
D2021
D2023
S1951
S1901
G BOARD
6V
IC2005
LAMP HV DET
1. Incomplete installation of the air filter or lamp cover
When either S1951 (filter) or S1901 (lamp cover) is
opened, the voltage of pin *¡ and pin *™ on IC1 be-
comes 5V. The circuit detects that and changes the volt-
age of pin %¢ on IC1 to 0V.
STBY
LED
2. Poor ventilation (standstill of the fan)
When one of the fan stops or is out of order, the voltage
of pin &ª on IC1 becomes 5V. The circuit detects that
and changes the voltage of pin %¢ on IC1 to 0V.
3. Burnt out of the lamp
IC8
When the lamp has burnt out, the voltage of pin &¶ on
CXA1875
IC1 becomes 5V. The circuit detects that and changes
the voltage of pin %¢ on IC1 to 0V.
4. Abnormal condition of the power source for the lamp
When the lamp is turning on with an abnormal condition
of the power source for the lamp , the voltage of pin &¶
on IC1 becomes 5V and the voltage of pin &• on IC1
stays 0V. The circuit detects that and changes the volt-
FAN1
age of pin %¢ on IC1 to 0V.
5. No power supply from the power source to the switch
When no power is supplied from G board, the voltage of
pin ^¶ on IC1 becomes 0V . The circuit detects that and
FAN2
changes the voltage of pin %¢ on IC1 to 0V.
FAN3
LAMP
DRIVER
LAMP
– 7 –
KL-X9200M/X9200U
RM-902