Sony KF-42WE620 Service Manual page 9

Clearing the Result Display
To clear the result display to "0", press the buttons on the Remote Commander sequentially when the diagnostic screen is displayed, as shown below:
1. Power off (Set to Standby model)
2. Display
Channel 5
ENTER
3. Channel 8
4. Wait until the initial setup display appears.
5. Disconnect the AC plug and then reconnect it.
Quitting the Self-Diagnostic Screen
To quit the entire self-diagnostic screen, turn off the power switch on the Remote Commander or the main unit.
Self-Diagnostic Circuit
Self-Diagnosis Function Operation
- 3 : Lamp cover
- 4 : Fan
- 4 : Temp
- 5 : Lamp drive
- 6 : +BOVP
- 7 : Audio
- 8 : D-OVP
- LAMP : Lamp
H3/A board
IC41
Temp
sensor
G3/A board
+3.3V
+2.5V
+1.8V
+17V
G1/A board
KF-42WE620/50WE620
Sound Volume -
If the lamp cover SW is opened then pin 1 of CN8034 on the A board is high. The LCD Engine u-com (pin 27 of
IC3208 on the C2 board) detects it and turns the lamp off.
If Fan1, Fan2, Fan3, or Fan4 stops then pin 2, 5, 8 or 11 of CN8035 on the A board is high. The LCD Engine
u-com (pin 24 of IC3208 on the C2 board) detects it and turns the lamp off.
If a temperature sensor on the H4 board detects a high temperature,
or the IIC-E line connector (CN8041:A board,CN3951 H4 board) is not attached securely, the LCD Engine u-
com IIC-E Line detects it and turns the lamp off.
If a lamp is not turned on, then pin 29 of LCD Engine u-com (IC3208 on the C2 board) is high and checks pin
28 of LCD Engine u-com. If pin 28 is low, it is judged no high voltage.
If +17V line drops then pin 53 of MAIN u-com (IC3405 on the C2 board) is low and automatically turns off the
main power.
If DC appears by the audio amp failure at the speaker line then it is detected by MAIN u-com (pin 59 of IC3405
on the C2 board) and automatically turns off the main power.
If +3.3V, +2.5V, or +1.8V line over, then pin 49 of MAIN u-com (IC3405 on the C2 board) is low and
automatically turns off the main power.
If a lamp is not turned on, then pin 29 of LCD Engine u-com (IC3208 on the C2 board) is high and checks pin
28 of LCD Engine u-com. If pin 28 is high the lamp is burned out.
C2 board
IC3208
LCD Engine u-com
LAMP COV
4:Temp
IIC-E
LAMP DRV
LAMP PROT
FAN PROT
IC3405
MAIN u-com
8:D-OVP
D-OVP
49
SP-DC-PROT
6:+B OVP
53 LOW-B-ERR
17V-DET
Power ON
A board
3:Lamp
CN8014
cover
27
3
5:Lamp
2
driver
1
28
HV-DET
Lamp CN8003
1
29
LAMP-PRT
4:Fan
24
2
FAN1-PRT
5
FAN2-PRT
8
FAN3-PRT
CN8022
IC8504
7:Audio Audio
59
amp
IC4704
Audio
amp
AU board
T/A board
S3999
SW
Lamp driver
Lamp
Fan1
Fan2
Fan3
KF-42WE620/50WE620
9