Servicing Note - Sony WM-FX495 Service Manual

This set detects the rotation of the idler gear (A) (side S) using the
photo reflector (PH751). The PH751 is mounted on the MAIN
board, therefore the idler gear (A) (side S) cannot be detected with
the MAIN board removed. As a result, the motor (M601) cannot
be controlled, causing malfunction.
Further, the MD CONT switch (S601) is also mounted on the
MAIN board, and with the board removed, the mechanism posi-
tion cannot be detected and the operation is not changed over.
Therefore, when the voltage check is executed with the MAIN
board removed, follow the procedure provided below.
1. Setting
1) Refer to "3. DISASSEMBLY", and remove the MAIN board.
2) Connect the MAIN board to the motor (M601) using jumper
wires. These can be connected easily with the use of the
extension tool (Part No. 1-769-143-11) (ten in one set).
3) Connect the AF oscillator to the TP752 and the BT401 (BATT–
).
4) Supply 1.5 V to the battery terminals using the regulated power
supply.
2. Preset state
To set the PLAY, FF, REW modes, the preset state must be set.
1) Check that the slider (NRA) and the MD CONT switch (S601)
are set to the center position. If not, set the preset state as fol-
low.
2) Move the MD CONT switch (S601) to the side, which the
slider (NRA) is facing.
3) The slider (NRA) will move when the regulated power supply
switch is set to OFF once and then set to ON. Move the MD
CONT switch (S601) according to this timing and set to the
center position.
– MAIN Board (Component Side) –
SECTION 1
SERVICING NOTES
3. FF, REW modes
1) Check that the preset state is set.
2) Input the square wave or sine wave to the TP752 and the BT401
(BATT–).
3) Press the
4. PLAY mode
1) Check that the preset state is set.
2) Input the square wave to the TP752 and the BT401 (BATT–).
3) Press the Y button will move the slider (NRA) once towards
the side REV and then to the side FWD. Move the MD CONT
switch (S601) according to this timing will set the PLAY mode
(side FWD). Press the Y button another time for a second
and move the MD CONT switch (S601) according to the move-
ment of the slider (NRA) will set the PLAY mode (side REV).
If the above fails, perform from preset again.
Note 1:
When using headphones, the timing for move the
Note 2:
CONT
sound.
– MAIN Board (Conductor Side) –
[FF] [REW]
button or button .
switch (S601) can be determined from the beep
RVS
REW
FF
FWD
connect to themotor (M601)
WM-FX495
MD
battery terminal #
AF oscillator
1k Ω
+
–
square wave
2 Hz, 2 VdB
2Vp-p
battery
terminal 3
3