Adjusting Sequence; Power Supply Adjustments; Power Supply Check; Adjustment - Sony SE350K Service Manual

2-1-6.

Adjusting Sequence

Make the electrical adjustment in the following sequence.
Power supply adjustment

Servo system adjustment

Audio system adjustment
2-2.

POWER SUPPLY ADJUSTMENTS

2-2-1.

Power Supply Check

(SRV938EK BOARD)
Mode
Measuring Instrument
MTR12 V check
Measurement Point
Specified Value
D6 V check
Measurement Point
Specified Value
+13 V check
Measurement Point
Specified Value
+38 V check
Measurement Point
Specified Value
SW 5 Vcheck
Measurement Point
Specified Value
+F, –F check
Measurement Point
Specified Value
–11 V check
Measurement Point
Specified Value
Checking Method:
1) Confirm that each voltage meets its specified value.
2-2-2. +6 V Adjustment
(SRV938EK BOARD)
Mode
Measuring Instrument
Measurement Point
Adjusting Element
Specified Value
E-E
Digital voltmeter
Pin 5, 6 of CN201
13.5 ±0.4 V
Pin qf of CN201
5.9 ± 0.2 V
Pin qs of CN201
13.6 ± 0.5 V
Pin 2 of CN202
35.0 ± 3.5 V
Pin qg, qh of CN201
5.2 ± 0.2 V
Pin 4, 6 of CN202
+ 0.6
2.9 V
– 0.3
Pin 3 of CN202
–11.5 ± 1.0 V
REC or PB
Digital voltmeter
Pin qf of CN201
VR251
5.9 ± 0.2 V
2-3. SERVO SYSTEM ADJUSTMENT
2-3-1.

RF Switching Position Adjustment

(MA-373 BOARD)
Purpose:
Adjust the interval between A ch and B ch of tape playback out-
put.
Improve the interchangeability with other tapes and sets.
When it is out of order, the interval appears on the screen, the
screen is disturbed.
Mode
Signal
Measurement Point
Measuring Instrument
Specified Value
Adjusting Method:
1) During playback, connect MA-373 board CN262 pin 3 and
the pin 5 for about 1 second to activate the RF switching
position adjustment mode.
2) Check appear "A P" on FL display.
3) Using the channel + and – buttons, adjust to 6.5 ± 0.5 H.
4) Press the pause button.
CH1
CH2
enlargement
CH1
6.5 ± 0.5 H
(416 ± 32 µsec) PAL
CH2
(410 ± 32 µsec) NTSC
7-2
PB
Alignment tape SP mode
color bar
CH1: Pin 1 of CN262
CH2: Pin 2 of CN262
(RF SWP)
Oscilloscope
6.5 ± 0.5 H (416 ± 32 µsec)
PAL
6.5 ± 0.5 H (410 ± 32 µsec)
NTSC
Approx. 1 Vp-p
Approx. 5 Vp-p
V
Vertical sync. signal
Fig. 7-2-3.