Sony MCE-K550 Service Manual page 5

Lighting of All Fluorescent Indicator Tube
Displays and Key Check Mode
1. Connect SL501 on the VIDEO board with solder.
2. Turn the power on.
3. All the Fluorescent Indicator tube displays light up.
4. Press any button to enter the key check mode. In the key check
mode, each time a button is pressed, figures displayed on the
Fluorescent Indicator tube displays increase. However, figures
will not increase for buttons which have been pressed once.
The button number corresponding to the button pressed will
also be displayed. Button numbers are displayed only while
the corresponding buttons are pressed.
5. After the test mode, remove the soldering installed.
7-segment display
88
88
Count up display
Initial display (K550)
Initial display (K750)
[ VIDEO BOARD ] — SIDE A —
D502
SL501
IC502
IC503
Button number display
SL503
SL502
IC504
Button Name
NEXTˆ
§OPEN/CLOSE
RETURN
PREV
º
‚
DNR
MPX (K750)
L/R/STEREO (K550)
SURROUND (K750)
REPEAT (K550)
KEY CONTROL N
(K750)
KARAOKE STAR
(K750)
KEY CONTROL #
(K750)
KEY CONTROL ˜
(K750)
KARAOKE PON
(K750)
PLAY MODE (K550)
JOG SELECTOR
(PUSH SELECT)
ACTIVE/COMET
p
∏
·
— 5 —
Button Number (Displayed only
while a button is pressed.)
Figure 0E
Figure 16
Figure 30
Figure 31
Figure 33
Figure 34
Figure 48
Figure 50
Figure 5d
Figure 67
Figure 68
Figure 6b
Figure 6c
Figure 77
Figure 81
Figure 88
All Fluorescent Indicator tube
displays light up
Music calendar light up alternately
(K550)
(odd numbor to even number)
KEY indicater light up alternately
(K750)
1 3 5 2 4
7 9 ↔
6 8
11 13 15 12 14
17 19 16 18
7-segments displays light up
alternately
The odd number digits and the even
number digit of the upper 7-segments
displays and the lower 7-segments
displays light up alternately.
10
20