Electrical Adjustments - Sanyo VHR-VT821A Service Manual

Read and perform this adjustment when repairing the
circuits or replacing electrical parts or PCB assemblies.
1. BASIC ADJUSTMENT
CAUTION
When you exchange IC and Transistor for a heat sink,
apply the silicon grease (YG6260M) on the contact
section of the heat sink. Before applying new silicon
grease, remove all the old silicon grease. (Old grease
may cause damages to the IC and Transistor.)
1-1: PG SHIFTER
CONDITIONS
MODE-PLAYBACK
Input Signal-Alignment Tape (JG001E)
INSTRUCTIONS
1. Connect CH-1 on the oscilloscope to TP4001 and CH-2
to pin 5 of CP4503.
2. Playback the alignment tape. (JG001E)
3. Press and hold the Tracking-Auto button on the remote
control more than 2 seconds to set tracking to center.
4. Press both CH UP button and STOP button on the set for
more than 2 seconds. If the indicator ATR disappear's,
the adjustment is finished. (Refer to Fig. 1-1-A, B)
6.5H

ELECTRICAL ADJUSTMENTS

CH-2
CH-1
Fig. 1-1-A
CH-2
CH-1
6.5H
Fig. 1-1-B
1-2: PB-Y LEVEL
CONDITIONS
MODE-PLAYBACK
Input Signal-Alignment Tape (JG001F)
INSTRUCTIONS
1. Connect the oscilloscope to pin 5 of CP4503 through 75
ohm resistor.
2. Playback the alignment tape. (JG001F)
Check if the VIDEO OUTPUT LEVEL is 1.05 ± 0.15Vp-p.
3.
(Refer to Fig. 1-2)
1-3: E-E LEVEL
CONDITIONS
MODE-STOP
Input Signal-PAL Color Bar
INSTRUCTIONS
1. Connect the color bar generator to pin 9 of CP4503.
2. Connect the oscilloscope to pin 5 of CP4503 through 75
ohm resistor.
Check if the VIDEO OUTPUT LEVEL is 1.05 ± 0.15Vp-p.
3.
(Refer to Fig. 1-3)
1-4: E-E AUDIO LEVEL
CONDITIONS
MODE-STOP
Input Signal-Audio Signal: 1KHz, 500mVrms
Input Select-AV
INSTRUCTIONS
1. Connect the audio generator to pin 7 of CP4503 and
pin 11 of CP4503.
2. Connect the AC voltmeter to pin 1 of CP4503 and pin 3
of CP4503 through 47K ohm resistor.
Check if the AUDIO OUTPUT LEVEL is 500mVrms ± 2
3.
dB.
28
1.05Vp-p
Fig. 1-2
1.05Vp-p
Fig. 1-3