Ak53 Chassis Manual Adjustments Procedure; Preliminary; System Voltage Adjustments; Afc Adjustments - Sharp 32LF-94EC Service Manual

13.AK53 CHASSIS MANUAL ADJUSTMENTS PROCEDURE

13.1.PRELIMINARY

Before starting with the alignment procedure, make sure that all the potentiometers on the chassis and
also screen and focus pots are in the medium position.

13.2.SYSTEM VOLTAGE ADJUSTMENTS

Inputs AC power (220V 50Hz)
PAL B/G test pattern via RF
(PAL I test pattern for PAL I TV's, SECAM D/K pattern, SECAM L/L'/K' TVs.)
Outputs Digital voltmeter to anode of D805
Display System voltage
Action Apply power. Check that the stand-by Led lights.
Select TV mode and tune to the applied test pattern via local test keyboard.
Chassis should start normally.
Adjust all analog controls (volume, bass, treble, brightness, contrast, colour) to minimum
settings.
Adjust VR801 according to the following different type of CRTs.
SYSTEM VOLTAGE(B+)
135V±0.5V
measured @anode of D805

13.3.AFC ADJUSTMENTS

AFC is automatically adjusted from software .

13.4.FOCUS ADJUSTMENTS

Inputs AC power
PAL B/G test pattern via RF input.
Outputs Picture tube drive.
Display Picture
Action Select TV mode and tune to the signal.
Adjust focus potantiometer (the upper pot on the rear side of the FBT transformer) for
optimum focusing drive.

13.5.SCREEN ADJUSTMENT (VG2 ALIGNMENT)

To adjust the screen of the TV set please follow the following steps;
Step1: Go to service menu by ;
-Press MENU button from remote controller
-Enter 4,7,2,5 from digit keys of remote controller
-You will see 7 items of SERVICE MAIN MENU
Step2:Go to VG2 STATUS item by ?/? buttons and press OK button from remote controller
Step3:In that case screen will be blanked and you will see one of four items as remark on the screen
UNKNOWN,INCREASE,DECREASE and OK.
Step4:If you see UNKNOWN, INCREASE, DECREASE then rotate the screen port of FBT until you see
OK indication on the screen that means that Screen of TV set properly.

13.6.AGC (AUTOMATIC GAIN CONTROL)

In order to do AGC adjustment, enter a 60µdBV RF signal level from channel A-12 (205.25 MHz)
Select AGC EXT parameter from service menu. Set AGC parameter to zero. Note the tuner AGC
voltage level. Increase AGC value until tuner AGC voltage goes 1V below noted voltage level. Check
that picture is normal at 90dBµV signal level.
Min. Value:
Max. Value:
AK53 D.O.C. Service Manual
TYPE OF CRT
THOMSON 28' 4:3 SF
000
063
A66EHJ13X12
33
22/03/2004