Vestel 11AK30 Service Manual

JVC AK30 / MONO - SERVICE MENU

RELEASE DATE: 08.04.2002
PREPARED BY: BAHADIR ISCAN

APPL.ENG.DEP.

ENTERING TO SERVICE MENU:

In order to enter service menu, first enter the main menu and then press the digits 4, 7, 2
and 5 respectively.
To select adjust parameters, use  or  buttons. To change the selected parameter, use  or
 buttons. Selected parameter will be highlighted.

Entire service menu parameters of AK30 CHASSIS are listed below. For some of
parameters the default values are given on the same table.

USING COLOUR BUTTONS ON SERVICE MENU:

- RED BUTTON (For Stereo models only): It switches the AVL to ON or OFF

mode on service menu. AVL word is visible on service menu when AVL is on.

- GREEN BUTTON : It switched the PICTURE MODE to 4:3 or 16:9 on service

menu. It is useful when it is necessary to adjust 16:9 picture mode vertical size.

- YELLOW BUTTON : It switches to VERTICAL SCAN DISABLE mode. It is

useful to adjust screen voltage.

- BLUE BUTTON : It is used to adjust AGC and IF automatically on service menu.

OSD:

Select OSD parameter on service menu. Adjust the horizontal position of OSD to the
middle of screen, by using the reference bar on bottom of service menu.

Min. Value: 000
Max. Value: 127
Recommended Value:082

IF Adjustments:

IF1: IF Coarse Adjustment 004
IF2: IF Fine Adjustment 065
IF3: IF Coarse Adjustment for L-prime 004
IF4: IF Fine Adjustment for L-prime 065

IF NEGATIVE ADJUSTMENT (WITHOUT L’ SYSTEMS)

Set the video pattern to a PAL colour bar pattern with frequency 38.9 MHz. Apply this IF
signal to PIN-10 and PIN-11 of tuner. Press PROG-1 and after that BLUE
(INSTALL)button from remote controller. Select the standard as BG or I. (if BG is not
available) Enter service menu. Select IF1 parameter from service menu and press BLUE
(INSTALL) button from remote controller. IF adjustment will be done automatically by

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software. See the IF indicator on service menu, it must be like on FIGURE-1 shown

FIGURE-1

belove.

IF POSITIVE ADJUSTMENT (WITH L’ SYSTEMS)

Set the video pattern to a SECAM-L colour bar pattern with frequency 33.9 MHz. Apply
this IF signal to PIN-10 and PIN-11 of tuner. Press PROG-1 and after that BLUE
(INSTALL)button from remote controller. Select the BAND VHF-1 (S1 – S4 for PLL
tuners) and standard as L’. Enter service menu. Select IF1 parameter from service menu
and press BLUE (INSTALL) button from remote controller. IF adjustment will be done
automatically by software. See the IF indicator on service menu, it must be like on
FIGURE-1 shown below.

AGC: Automatic Gain Control

In order to do AGC adjustment, enter a 60µdBV RF signal level from channel C-12
(224.25 MHz) Select AGC parameter from service menu. Press BLUE (INSTALL)
button from remote controller. The adjustment will be done automatically by software.
See the AGC indicator on service menu, it must be 1. Check that picture is normal at
90dBµV signal level.

: 1 1

IF INDICATOR AGC INDICATOR NONE

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SCREEN ADJUSTMENT: (FBT Screen)

SCREEN
ADJ.POT.

Enter service menu by pressing “MENU” and “4, 7, 2, 5” from remote controller. Then
press yellow button to disable vertical scan. Adjust screen via screen pot. For a thin
horizontal line. Press yellow button again to enable vertical scan. Press “TV” button to
leave service menu.

VLIN: Vertical Linearity

Enter a PAL B/G circle test pattern via RF. Change VLIN till you see circle as round as
possible.

Min. Value: 000
Max. Value: 063
Recommended Value:045

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VS1A: Vertical Size for 50 Hz / 4:3

Enter a PAL B/G circle test pattern via RF. Change VS1A (Vertical Size) until horizontal
black lines on both the upper and lower part of the test pattern become very close to the
upper and lower horizontal sides of picture tube and nearly about to disappear. Check and
readjust Vertical Size item if the adjustment becomes improper after some other
geometric adjustments are done.

Min. Value: 000
Max. Value: 063
Recommended Value:030

VS1B: Vertical Size for 50 Hz / 16:9

Enter a PAL B/G circle test pattern via RF. Enter service menu and press GREEN
(PICTURE) button from remote controller to switch to 16:9 picture mode on service
menu. Change VS1B (Vertical Size) till the picture becomes 16:9 format. Check and
readjust Vertical Size item if the adjustment becomes improper after some other
geometric adjustments are done.

Min. Value: 000
Max. Value: 063
Recommended Value:056

VP1: Vertical Position for 50 Hz

Enter a PAL B/G circle test pattern via RF. Change Vertical Position till the test pattern is
vertically centered. Horizontal line at the center pattern is in equal distance both to upper
and lower side of the picture tube. Check and readjust Vertical Position item if the
adjustment becomes improper after some other geometric adjustments are done.

Min. Value: 000
Max. Value: 015
Recommended Value:010

HP1: Horizontal Position for 50 Hz

Enter a PAL B/G circle test pattern via RF. Change Horizontal Position until the picture
is horizontally centered. Check and readjust Horizontal Position item if the adjustment
becomes improper after some other geometric adjustments are done.

Min. Value: 000
Max. Value: 063
Recommended Value:035

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