Alignment Instructions Analog Board - Yamaha DRX-2 Service Manual

I ALIGNMENTS

1. Alignment Instructions Analog Board

Test equipment:
1. Dual-trace oscilloscope
Voltage range : 0.001 ~ 50 V/div
Frequency : DC ~ 50 MHz
Probe : 10:1, 1:1
2. DVM (Digital voltmeter)
3. Frequency counter
4. Sinus generator
Sinus : 0 ~ 50 MHz
5. Test pattern generator
How to read the adjustment procedures:
DVDR mode:
Example using:
DVDR TUNER
Connecting point
(Test Point) of
measuring
equipment
Adjustment
component
TP ADJ. MODE
Pin 2 of
R3054 TUNER
Con.1911
(FMRV)
DISC MEAS.EQ.
Frequency-
Disc Counter
Measuring
Disc needed for
equipment
adjustment
Front End (FV)
Service tasks after replacement of IC 7710, coil L5710 and
L5711:
1.1 AFC Adjustment:
Purpose:
Correct adjustment of demodulator AFC - circuit
Symptom, if incorrectly set:
Bad or disturbed TV channel reception.
PAL - AFC adjustment [5711]:
IC 7710 Pin
17 (F708)
Storage in NVRAM via command mode interface of DSW:
After adjustment, the AFC reference value has to be
stored in the NVRAM.
Test signal
This reference value is 256 * measured voltage/Ucc. Ucc
required for the
adjustment and
is 5.0V.
feed-in point
Store the reference value via command 1119 , followed by
the ref. value.
INPUT
Example: DS:> 1119 128
SPEC.
1.2 HF - AGC adjustment [3724]:
Service tasks after replacement of IC 7710:
3,800MHz
±10kHz
Purpose: Set amplifier control.
Symptom, if incorrectly set:
Picture jitter if input level is too low and picture
Adjustment
Specification
distortion if input level is too high.
Tuner 1705
(F710, IF-
TP ADJ. MODE
L5711 TUNER
MEAS.EQ.
DISC
DC Voltmeter
Frequ.
Generator
TP ADJ. MODE
R3707 Set tuned to
Pin 11 channel 25
503.25 MHz
out)
MEAS.EQ.
DISC
Oscilloscope
Video Pattern
Generator
DRX-2
INPUT
38.9 MHz
500 mVpp at
Tuner 1705,
Pin 11 (F710,
IF-out)
SPEC.
2.5 V ±0.1 V
INPUT
5mV(74dBµV)
on aerial input
PAL white
picture, audio
IF on, no
modulation
SPEC.
500mVpp +/-
0.5dB (use a
10:1 probe )
95