Sony MDR-IF230, Service Manual

Page: 3 / 8

– 4 – – 3 –
TUNING Adjustment
Preparation :
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.
SECTION 2
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).
Transmitter
AUDIO IN B jack (J1)
1kHz 245mV (–10dB)
AF OSC
ATT
Jig
600
Ω
C35 C55
C 3
L 1
TP51
TP31
L53
L32
TP3
TP2
TP
(VCC)
TP
(GND)
TP
(SW)
regulated DC
power suppluy
1.2V DC
distortion
meter
TP51
(R-CH)
TP31
(L-CH)
RV1 (VOL)
TP (VCC)
TP (GND)
L32 : Tuning Adjustment (L-CH)
L53 : Tuning Adjustment (R-CH)
[RX BOARD] (Conductor side)
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.
Connection and Adjustment Location :
MUTE ON POINT Adjustment
Connection and Adjustments Location :
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.
C35 C55
C 3
L 1
TP51
TP31
TP3
TP2
TP
(VCC)
TP
(SIG)
TP
(GND)
TP
(SW)
RV2
regulated DC
power suppluy
1.2V DC
level meter
TP51
(R-CH)
TP51
(R-CH)
TP3
RV2 : Mute ON point
Adjustment
TP2
TP (SIG)
10k
Ω 0.1
µ
F
TP (VCC)
TP (GND)
[RX BOARD] (Conductor side)
FM RF signal
generator
Carrier frequency : 2.8MHz
Modulation : 1kHz
Deviation : 16kHz
Output level : 34dB
µ
V