Alignments - Yamaha DRX-1 Service Manual

ALIGNMENTS

1. Alignment Instructions Analogue Board
Alignments Analog PCB Eur
ADJUSTMENT INSTRUCTIONS ANALOGUE 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 7703, coil L5702 and
L5703:
1.1 AFC Adjustment:
Purpose: Correct adjustment of demodulator AFC - circuit
Symptom, if incorrectly set:
Bad or disturbed TV channel reception.
PAL - AFC adjustment [5703]:
TP ADJ. MODE
IC 7703
Pin 17
L5703 TUNER
(I976)
DISC MEAS.EQ.
DC Voltmeter
Frequ. Generator
1.2 HF - AGC adjustment [3707]:
Service tasks after replacement of IC 7703:
Purpose: Set amplifier control.
Symptom, if incorrectly set:
Picture jitter if input level is too low and picture distortion
if input level is too high.
1.3 Attenuating the 40.4 MHz [5702]: (SECAM only)
Service tasks after replacement of coil 5702:
Purpose: To attenuate the band I carrier rests.
Symptom, if incorrectly set:
Bad picture quality when the filter attenuates the picture
carrier (38.9MHz).
Test signal
required for the
adjustment and
feed-in point
INPUT
SPEC.
3,800MHz
±10kHz
If the adjustment is correct the signal at pin 1 of OFW
Adjustment
Specification
[1700] must be smaller than the input signal amplitude by
at least 5 dB.
2. Reprogramming Procedure of NVM on the
The NVM, item 7815, on the Analogue board contains the
following factory settings:
1. Bargraph 0dB correction factor
2. Clock correction factor
3. AFC reference value
4. Slash version
The settings 1,2 and 3 are stored in the NVM during the
production of the analogue board.
INPUT
The slash version is stored at the end of the production
38,9MHz 500mV
pp
line of the set.
at Tuner 1705, Pin 11
In case of failure, the NVM must be replaced by an empty
(F700, IF-out)
device. By way of commands via the Diagnostic Software
SPEC.
or via ComPair, the factory settings must be restored in
2,5V ±0,2V
the NVM.
TP ADJ. MODE
Tuner
1705
Set tuned to
R3707
Pin 11
channel 27
(F700,
IF-out)
DISC
MEAS.EQ.
Oscilloscope
Video Pattern
Generator
TP ADJ. MODE
OFW
TUNER
1700
L5702
Pin 1
(F704)
DISC
MEAS.EQ.
Oscilloscope,
Sinus Generator,
Counter
Analogue PCB
DRX-1
INPUT
4,5mV(74dBµV)
on aerial input
PAL white picture,
audio IF on,
no modulation
SPEC.
550mV +/-50mV
pp
(use a 10:1 probe )
INPUT
40.4 MHz, 300mV
rms
at Tuner 1705, Pin 11
(F700, IF-out)
SPEC.
adjust minimum
amplitude
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