Circuit Adjustments - Sony TRINITRON KV-VF14M70 Service Manual

Necessary items and indications for total adjustment of electric
circuit of this unit will be described in this chapter.
[ INSTRUMENTS TO BE USED ]
1) Color TV
2) Signal or dual trace type oscilloscope, band more than 30 MHz,
delay, as provided.
3) Frequency counter (4 digits or more)
4) PAL pattern generator
5) Digital voltmeter
6) Audio level meter
7) Audio generator
8) Attenuator
9) Distortion meter
10) Alignment tape
Part code : H7099052H (MH-2)
[ CONNECTION ]
Unless otherwise specified, connect and adjust the measurement
equipment as follows.
Pattern generator
VIDEO LINE OUT (75Ω)
Fig.3-1
SECTION 3

CIRCUIT ADJUSTMENTS

VIDEO INPUT
– 74 –
[ SET-UP FOR ADJUSTMENT ]
The video signal from the pattern generator is used as adjustment
signal for electrical adjustment. This video signal should meet the
requirement. Connect the oscilloscpe to the video input terminal
on the MF 1 board and make sure that the amplitudes of sync signal
of video signal, video portion and burst signal are flat at
approximately 0.3, 0.7 and 0.3 V, respectively, and that the level
ratio of the burst signal and "red signal" are 0.30 : 0.66, Fig.3-2
shows video signals (color bars) used in adjusting the electrical
adjustment.
Approx.
0.7V
Approx.
Red
0.3V
Horizontal sync signal
Fig.3-2
Alignment Tape (MH-2)
Time Video signal
1 10 minutes Starir-step
2 5 minutes
3 10 minutes Color bar
4 3 minutes RF sweep
[ SPECIFIED INPUT/OUTPUT LEVEL IMPEDANCE ]
Input/Output terminal
Video input Pin jack
Input signal : 1Vp-p, 75Ω, unbalanced
AUDIO LINE IN Pin jack
Input level : -7.5dBs
Input impedance : More than 47kΩ
White (approx. 100%)
Burst signal
(To be flat)
Approx.
0.3V
Audio signal
6kHz
- 3kHz
1kHz
-
Sync negative
(0dBs=0.775Vrms)