AV-20F703
SERVICE ADJUSTMENTS
ELECTRICAL ADJUSTMENTS
1. ADJUSTMENT PROCEDURE2. BASIC ADJUSTMENTS
Read and perform these adjustments when repairing the circuits
or replacing electrical parts or PCB assemblies.2-1: CONSTANT VOLTAGE
1.Set condition is AV MODE without signal.
CAUTION2.Connect the digital voltmeter to the TP002.
YUse an isolation transformer when performing any service3.Adjust the VR502 until the DC voltage is 116 ? 1V.
on this chassis.
YBefore removing the anode cap, discharge electricity2-2: RF AGC
because it contains high voltage.1.Place the set with Aging Test for more than 15 minutes.
YWhen removing a PCB or related component, after2.Receive the VHF HIGH (63dB).
unfastening or changing a wire, be sure to put the wire3.Connect the digital voltmeter between the pin 5 of CP101
back in its original position.and the pin 1 (GND) of CP101.
YWhen you exchange IC and Transistor for a heat sink,4.Activate the adjustment mode display of Fig. 1-1 and
apply the silicon grease (YG6260M) on the contact section
press the channel button (02) on the remote control to
of the heat sink. Before applying new silicon grease,select ORF AGC�.
remove all the old silicon grease. (Old grease may cause5.Press the VOL. UP/DOWN button on the remote control
damages to the IC and Transistor.)
until the digital voltmeter is 2.1 ? 0.05V.
Prepare the following measurement tools for electrical
2-3: CUT OFF
adjustments.
1. Oscilloscope1.Adjust the unit to the following settings.
2. Digital VoltmeterG. DRIVE=64, B. DRIVE=64, R. BIAS=64, G. BIAS=64,
B. BIAS=64
On-Screen Display Adjustment2.Place the set with Aging Test for more than 15 minutes.
3.Activate the adjustment mode display of Fig. 1-1 and
1. In the condition of NO indication on the screen.4.press the channel button (01) on the remote control to
Press the VOL. DOWN button on the set and the Channel
button (9) on the remote control for more than 1 second toselect OCUT OFF�.
5.Adjust the Screen Volume until a dim raster is obtained.
appear the adjustment mode on the screen as shown in
Fig. 1-1.
2-4: WHITE BALANCE
NOTE: Adjust after performing CUT OFF adjustment.
TV1.Place the set with Aging Test for more than 10 minutes.
2.Receive the gray scale pattern from the Pattern Generator.
3.Using the remote control, set the brightness and contrast
to normal position.
4.Activate the adjustment mode display of Fig. 1-1 and
press the channel button (13) on the remote control to
00 OSD 15
select OR. BIAS�.
Fig. 1-15.Press the CH. UP/DOWN button on the remote control to
select the OR. BIAS�, OG. BIAS�, OB. BIAS�, OB. DRIVE� or
2.Use the Channel UP/DOWN button or Channel button (0-OG. DRIVE�.
9) on the remote control to select the options shown in6.Adjust the VOL. UP/DOWN button on the remote control
Fig. 1-2.to whiten the R. BIAS, G. BIAS, B. BIAS, B. DRIVE, and
3.Press the MENU button on the remote control to end theG. DRIVE at each step tone sections equally.
adjustments.7.Perform the above adjustments 5 and 6 until the white
color is looked like a white.
NO.FUNCTIONNO. FUNCTIONNO.FUNCTION
00OSD H14G.BIAS28RGB CONTRAST2-5: FOCUS
01CUT OFF15B.BIAS29PARABORA1.Receive the monoscope pattern.
02RF.AGC16BRI.CENT30TRAPEZIU
03---17SUB CONT31COR TOP2.Turn the Focus Volume fully counterclockwise once.
04H.POSI18CONT.MAX32COR BTM3.Adjust the Focus Volume until picture is distinct.
05V.POSI19CONT.CENT33V EHT
06H.SIZE20CONT.MIN34H EHT
07V.SIZE21BRI.MAX35FM.LVL
08V.CENT22BRI.MIN36LEVEL
09V.LIN23COL.MAX37SEP 1
10VS CORR24COL.CENT38SEP 2
11G.DRV25COL.MIN39T.STE
12B.DRV26TINT40X-RAY
13R.BIAS27SHARPNESS88READ DATA
Fig. 1-2
No. 520019 |
ACEC
