AV-28BK5ECB
AV-28BK5ECS
SERVICE ADJUSTMENTS
[ADJUSTMENT]
How to adjust the each service data, please see OADJUSTMENT MODE � on page 13 for entering the service mode ,
selecting service item and adjusting the service data value.
IMPORTANT NOTICE
Do not attempt to adjust the following service adjustments except requiring the readjustments in servicing
otherwise it may cause loss of performance and product safety.
IF VCO ADJUSTMENTFOCUS ADJUSTMENT
PAL BG VCO ADJUSTMENTReceive cross-hatch pattern and adjust focus by using
1. Apply 38.9MHz signal with 90 ?10dBuV/75&FOCUS VR to obtain the defined vertical and horizontal
terminated to IF terminal on the tuner.lines.
2. Enter to the service mode and select mode
OREGULAR �, item OREGULAR 1VC1 �.
3. Press the or buttonto set data value to be
O10�.
GREY SCALE ADJUSTMENT
SCREEN ADJUSTMENTRF-AGC ADJUSTMENT
1. Receive colour bar pattern with 63dBuV/75&1. Select AV1 mode and no signal input.
terminated signal gain.2. Enter to the service mode and select mode
2. Connect digital voltmeter to TP-AGC and GND.OREGULAR �, item OREGULAR 4SCR �.
3. Enter to the service mode and select mode3. Check that mode is switched to AV and no signal
OREGULAR �, item OREGULAR 3AGC �.inputs.
4. Press the or buttonto adjust voltage to be4. Turn the SCREEN VR to set data value to be O11�.
3.2Vdc.
GREY SCALE ADJUSTMENT
5. Enter to the service mode and select modeVIDEO LEVEL ADJUSTMENT
OREGULAR �, item OREGULAR 5GRY �.
VIDEO LEVEL ADJUSTMENT-16. Adjust [R-Drive] and [B-Drive] control to obtain proper
1. Receive colour bar pattern.white balance by using buttonor .
2. Connect oscilloscope to terminal TPVIDEO and GND.a) Select [R-Drive] or [B-Drive] by using the or
3. Adjust amplitude Oa� to be 2.0Vp-p by using VR221.button.
b) Adjust [R-Drive] or [B-Drive] by using the or 100% White
button.
"a"
STATUS
[R-Drive]
REGULAR
4GRY22
VIDEO LEVEL ADJUSTMENT-222[B-Drive]
1. Receive colour bar pattern.Adjustable Range:
2. Connect oscilloscope to terminal 8 of K73A and GND.00 ~ 3F, 4F ~ 7F, 80 ~ BF, C0 ~ FF
Connect oscilloscope to terminal 11 of K73B and GND.
3. Adjust the amplitude of waveforms to be same by
using VR7351.*The cut off adjustment is not required for this model. The
cut off adjustment is carried out automatically in the TV
set itself.
No. 5175815 |
ACEC
