Samsung K155A TXJ1366, Руководство по обслуживанию

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Alignment and Adjustments
Samsung Electronics 4-3
4-2 Alignment and Adjustment
4-2-1 General Alignment Instructions
1. Usually, a color TV needs only slight
touch-up adjustment upon installation. Check
the basic characteristics such as picture height,
focus and a horizontal and vertical sync.
2. Observe the picture and check for good back
and white details. There should be no
objectionable color shading: If color shading is
present, demagnetize the receiver. If color
shading persists, perform purity and
convergence adjustments described below.
3. To protect against shock hazard, use an
isolation transformer.
4-2-2 Power Supply Check
Check the following:
A: Power plug is connected; “Stand-by” mode
B: Power On when “Power ON” button is pressed
C: Power On by FBT Each supply is marked on
its lead-in wire. ( )
4-2-3 Focus Adjustment
Adjust the focus control on the FBT for well
defined scanning lines.
4-2-4 Fail Safe Circuit Check (FS) (OPTION)
1. The failsafe check must be the final step in
servicing.
2. Turn the power switch ON and adjust
customer controls for normal operation.
3. Temporarily short pin X to pin R on the main
board (RX06, RX04) with a jumper wire.
Raster will disappear.
4. The TV must remain in this state even after
removing the jumper wire. This shows that
the failsafe circuit is working properly.
5. To recover picture and sound, temporarily
turn off the TV and allow the failsafe circuit
more than 30 seconds to reset. Then switch
power ON to produce normal picture and
sound.
4-2-5 IC902 Replacement
1. When IC902 is replaced, all values are reset to
“Initialized MICOM Data” and readjustment
is necessary.
2. Press the POWER button 10 seconds after
plug-in.
3. To enter the Service Mode, refer to Fig. 4-1
(Service Mode Adjustment).
4-2-6 PIF VCO Adjustment
1. Use a Pattern Generator or an off-air signal.
2. Open pin 11 of Micom (IC901) or one side of
lead pin for R237.
3. Adjust VCO in the service mode to set IC101
Pin 44 (AFT) to 2.5V ± 0.4V.
4. Connect the opened site.
4-2-7 RF-AGC Adjustment
1. Input a PHILLIPS pattern.
2. Set the input signal to 60 dB.
3. Enter into the AGC in the service mode.
4. Adjust AGC until color bar noise disappears.