Adjustments; Mechanical Adjustments; Electrical Adjustments; Preparation Before Adjustment - Sony SLV-478 Service Manual

6-1 MECHANICAL ADJUSTMENTS

For the mechanical adjustments, please refer to the
"VHS MECHANICAL ADJUSTMENT MANUAL
(S MECHANISM)" (9-921-647-11).

6-2. ELECTRICAL ADJUSTMENTS

HiFi model: SLV-677HF/678HF/688HF/L67HF/L68HF/
L77HF/L78HF/X60HF
Mono model: SLV-478/L47/L48/L57/L58/X50
See the adjusting part location diagram from on page 6-8
for the adjustment.
2-1.

PREPARATION BEFORE ADJUSTMENT

2-1-1. Equipment Required

The measuring instruments used for this alignment include:
1) Monitor TV
2) Oscilloscope, dual-trace, bandwidth of 30MHz or more, with
delay mode (A probe 10:1 should be used unless otherwise
specified.)
3) Frequency counter
4) Pattern generator
5) Digital voltmeter
6) Audio generator
7) Audio level meter
8) Audio distortion meter
9) Audio attenuator
10) Alignment tapes
KRV-51N2 Part No.: 8-192-605-32

2-1-2. Equipment Connection

Unless otherwise specified, connect and adjust the measuring
instruments as shown in the following diagram.
VIDEO LINE IN
Pattern generator
Video output
(75 Ω )
Fig. 6-2-1.
SECTION 6

ADJUSTMENTS

Monitor TV
VCR
VIDEO LINE OUT
SLV-478/677HF/678HF/688HF/L47/L48/L57/
L58/L67HF/L68HF/L77HF/L78HF/X50/X60HF

2-1-3. Input Signal Check

Video signal produced by a pattern generator is used as an adjustment
signal to perform electrical alignment for this unit. This video signal
must satisfy the specification.
Unless otherwise specified, place the switches and controls of this
unit in the following positions:
• INPUT SELECT switch ............................. LINE or LINE 1
Connect an oscilloscope to the Video Input terminal. Check that the
synchronizing signal of the Y signal has an amplitude of
approximately 0.7V and that the burst signal has an amplitude of
approximately 0.3V and its waveform is flat. And check that the
level ratio of burst signal to "red" signal is 0.30 : 0.66. The video
signal (color bar) used for electrical aligning this unit is shown in
Fig. 6-2-2.
About 0.7 V
About
0.3 V
Horizontal sync signal
Fig. 6-2-2. Color Bar Signals of Pattern Generator

2-1-4. Alignment Tape

• Contents of KRV-51N2
Mode Period
1 7 minutes
SP
2 3 minutes
3 7 minutes
EP
4 3 minutes
6-1
(Remote commander)
White (100%)
About
0.3 V
Red
Burst signal
(It must be flat.)
Audio signal
Video signal
Hi-Fi Normal
Color bar
Monoscope
400Hz 400Hz
Color bar
Monoscope