Sony XM-1502SX Training Manual page 55

Figure 4-18 - Display
Communications
Signal Location
1 FL CN524/pin
Clock 19
2 FL CN524/pin
Latch 18
3 FL CN524/pin
Data 17
4 FL CN524/pin
Blank 16.
Time base = 100 usec/division
Left and Right Knob Switch Tests
Table 4-10 shows the tests for the left (volume) and right (function) knobs. Test these switches with voltage
measurements (power ON) or resistance measurements (unit off) using test point pads near CN524 (Figure 4-
17).
Test for
Left knob -
Rotation
Left knob -
Press In
Right knob
- Rotation
Right knob
- Press In
Voltage
p-p
4Vp-p
(5V/div)
4Vp-p
(5V/div)
4Vp-p
(5V/div)
4Vp-p
(5V/div)
Table 4-10 - Knob switch Checks
Test Location (Fig 4-17)
CN524/pin 10 – RE_La
CN524/pin 15 – Key 0
CN524/pin 14 – RE_Rb
CN524/pin 15 – Key 0
FIGURE 4-18 - DISPLAY COMMUNICATIONS
Unit ON
Detent = 5Vdc
Off detent = 0Vdc
Normal = 5Vdc
Pressed = 4.4Vdc
Detent = 0Vdc
Off detent = 5Vdc
Normal = 5Vdc
Pressed = 3.8Vdc
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4. Car Music Storage Unit
Unit OFF
Detent = 103k ohms
Off detent = 0 ohms
Normal = 10.5k
Pressed = 8k ohms
Detent = 0 ohms
Off detent = 104k ohms
Normal = 10.5k
Pressed = 9k ohms