Horizontal Line - JVC AV-2771S Service Manual

AV-2771S |
Measuring
instrument
VERTICAL HEIGHT] Pattern
& LINEARITY
adjustment
VERTICAL
CENTER
adjustment
HORIZONTAL
CENTER
adjustment
generator
Pattern
generator
eCRT SOCKET CIRCUIT
HORIZONTAL LINE
display
Test point Adjustment part
V HEIGHT VR
(R423)
V LIN. VR
(R426)
V. CENTER switch
($401)
H. CENTER VR
(R508)
SERVICE switch
(S301)
Description
. Receive a picture that enable a vertical symmetry to
be checked.
. Turn the V HEIGHT VR to compress the picture
vertically.
. Adjust the V LIN. VR to where the picture is
symmetrical top and bottom.
. Again adjust the V HEIGHT VR to return the
normal height.
. The V. CENTER switch can be used to shift the
picture up and down.
* Use this function as required for "VERTICAL
HIEGHT & LINEARITY", and other adjustments.
. Turn the H. CENTER VR and adjust for the
optimum left and right position.
x Where possible, use a symmetrical pattern such as
a circle or crosshatch.
. Turning the SERVICE switch from the N side to
the S side will bring the horizontal line display to the
screen.
© ®
© : will appear ® : normal
aH line picture
<Top side>
eMULTI-CHANNEL SOUND CIRCUIT
®@ Do not touch the VRs inside the MTS PCB ASS'Y.
ePIP INTERFACE CIRCUIT
COMB FILTER
adjustment
30 (No.50577)
Pattern
generator
Oscilloscope
(H-rate 10:1)
C251 pin-@
DL PHASE
transformer
(T271)
COMB FILTER
VR
(R273)
3.58MHz elements
= minimum
. Receive the color bar signal.
. Connect the oscilloscope to pin-(@ of 1C251.
. Magnify the chroma signal portions of the color bar
waveform so that the 3.58MHz elements become
easy to observe.
. Adjust the DL PHASE transf. and minimize the
3.58MHz elements.
. Regulate the COMB FILTER VR to further mini-
mize the 3.58MHz elements.
. Repeat steps 4 and 5 to fully minimize the 3.58MHz
elements.