Electrical Adjustment - Sony MDR-IF230 Service Manual

ELECTRICAL ADJUSTMENT

Note :
1. The transmitter section adjustments should be completed before
performing the headphones section adjustment.
2. On adjusting the headphones section, use the transmitter as a
jig.
Headphones Transmitter
TMR-IF130
MDR-IF230 or
TMR-IF230R
MDR-IF330R TMR-IF330R
3. The headphones section adjustment must be made with PD board
connected to the RX board with the specified wire.
4. The MUTE ON POINT adjustment must be made while taking
care of the photodiodes (D1, D2, D101, D102) not to be ex-
posed directly to external lights (such as incandescent lamp and
sun light).
Connection and Adjustment Location :
[RX BOARD] (Conductor side)
TP31
(L-CH)
TP51
(R-CH)
RV1 (VOL)
TP51
TP31
L53
TP3
TP2
SECTION 2
TUNING Adjustment
Preparation :
AF OSC
Jig
ATT
Transmitter
600 Ω
AUDIO IN B jack (J1)
1kHz 245mV (–10dB)
1. Feed a signal to jig (transmitter) and connect a power supply to
DC IN jack (J4).
2. Apply DC 1.2V between TP (VCC) and TP (GND) on the RX
board.
3. Set the RV1 (VOL) on the RX board to the minimum position.
Procedure :
1. Connect the distortion meter to TP31 (L-ch) and TP51 (R-ch).
2. Turn on the power.
3. Adjust with L32 (L-ch) and L53 (R-ch) to minimize the reading
on the distortion meter.
regulated DC
power suppluy
distortion
1.2V DC
meter
TP (VCC)
TP (GND)
TP
(GND)
L32
TP
(VCC)
TP
(SW)
L32 : Tuning Adjustment (L-CH)
L53 : Tuning Adjustment (R-CH)
– 3 –
MUTE ON POINT Adjustment
Connection and Adjustments Location :
[RX BOARD] (Conductor side)
RV2
RV2 : Mute ON point
Adjustment
TP3
TP3
TP2
TP2
FM RF signal
generator
10k Ω 0.1 µ F
TP (SIG)
Carrier frequency : 2.8MHz
Modulation : 1kHz
Deviation : 16kHz
34dB µ V
Output level :
Procedure :
1. Short the circuit between TP2 and TP3.
2. Note down the level meter read at this time.
3. Release the short-circuit between TP2 and TP3.
4. Adjust RV2 so that the level meter read is 5dB to 10dB below
the value noted down at step 2.
regulated DC
power suppluy
1.2V DC
level meter
TP51
(R-CH)
TP (VCC)
TP (GND)
TP
(GND)
TP51
TP31
TP
TP
(SW)
(VCC)
TP51
(R-CH)
TP
(SIG)
– 4 –