Sherwood RV-4050R User manual

SERV. A455
SERVICE MANUAL |
RV-4050R
AUDIO/VIDEO
PRO-LOGIC
RECEIVER
Qsherwood
DTeMLIMNE M AUDIO. VIDEO MECEIVER Rv 40508
=» CONTE
Safety PrecautiOnS--------+-s see ee 2
Specifications A 3
Wirtng Diagram LULL. 7
Block Diagram BO 9
Circuit Description ---------e rt 11
Alignment Procedures = 2... 7
Troubleshooting -----:---.--e ester 20
G
Sherwood
NTSs
Mechanical
Parslist
=
=
==
=
=
=
==
28
Exploded
View...
cect
25
Printed
Circuit
BoardS-----t
27
Electrical
Parts
List
<=
32
IC'S
Lead
Identifications
&
Internal
Diagram
---38
Transistors
Lead
Identification
--------
43
Schematuc
Dieagramsti
[1
il)
45

SAFELY PHEULAYU LIVINDS
WARNING
Before servicing this unit, familiarize yourself with the following precautions: -
1.
N
Many electrical and mechanical parts in this
chassis have special safety characteristics that
often pass unnoticed and the protection
afforded by them cannot necessarily be
obtained by using replacement components
rated for higher voltge, wattage, etc.
Replacement parts that have these special
safety characteristics are identified in this
manual and its supplements: electrical
components having such features are
identified by -t. in the schematic diagram
and the parts list.
Before replacing any of these components,
read the parts list in this manual carefully. The
use of substitute replacement parts that do
not have the same safety characteristics as
specified in the parts list may create shock,
fire, or other hazards.
. Before returning the set to the customer,
always do an AC teakage current check on the
exposed metal parts of the cabinet, such as
terminals, screw heads, and metal overlays,
to be sure the set is safe to operate danger of
electrical shock. Plug the AC line cord directly
into a 120 V AC outlet (120 V AC version only).
(Do not use a line isolation transformer
during this check.) Be sure your AC voltmeter
has a sensitivity of 5000 <2 per volt or greater.
Then connect a 1500 {2 10 watt resistor,
paralleled by a 0.15 pF 150 V AC capacitor,
between a known good earth ground (such as
a water pipe, or conduit) and the exposed
metalic is parts, one at a time. Measure the
AC voltage across the combination of a 1500
Q2 resistor and a 0.15 pF capacitor. Reverse the
AC plug at the AC outlet and repeat AC
voltage measurements for each exposed
metalic part. Voltage measured must not
exceed 0.75V RMS. This corresponds to 0.2
mA AC. Any value exceeding this limit:
constitutes a potential shock hazard and must
be corrected immediately.
At 5000 2 per voit or greater sensitivity ,
the reading should not exceed 0.75 V.
AC Voltmeter
Good earth ground, such as
@ water pipe or Conduit.
0.15 ~F 1S0V AC
Place the probe on each exposed metalic part.
,| Audio Section-Front(Mode : Dolby-logic)
SPECIFICATIONS
Audio Section-Front (Mode: Normal)
RMS output power :
at distortion below 0.3 % 50 Hz
both channels driven at 8 Q
at distortion below 0.3 % 1 kHz
both channels driven at 8 Q
inter-modulation distortion
at 80 W output 60 Hz: 7 kHz =4: 1 SMPTE
Harmonic distortion at 45 W output : 40 Hz
1 kHz
20 kHz
Frequency response at AUX
8 Q load, 1 W output 20 Hz - 40 kHz
Input sensitivity for 50 W output : CD/AUX
Tone control BASS, 100 Hz
TREBLE 10 kHz
Channel separation with 4.7 kQ shorted
at AUX input 1 kHz
10 kHz
Signal to noise ratio, input shorted
with IHF-A
CD, TV/AUX,
TAPE(MONI)
(Condition
:
input
VCR,
input
level
1
kHz
350mV
vol.
level)
RMS
output
power
at
distortion
below
0.9%
1
kHz,
8
Q
Signal to noise ratio, input shorted
with IHF “A* (Dolby prologic, 3 Stereo)
Frequency response 8 Q load, 1 watt output
at -3 dB (Dolby prologic)
Audio Section-Center
40~20000 50~20000
RMS output power at distortion below 0.9% 1 kHz, 8 2
Signal to noise ratio, input shorted
:
;
dB
2
78
=
73
with
JHF "A*
(Dolby
prologic,
3
Stereo)
Frequency
response
8
Q
load,
1
watt
output
[Normal
|
Hz _|
at -3 dB (Dolby proiogic) [Wide | Hz
Audio Section-Rear =
RMS
output
power
at
distortion
below
0.9
%
1
kHz,
16
Q
100-17000
Signal to noise ratio input shorted
with IHF °A* (Dolby prologic)
Delay 20 ms
Frequency response 8 Q toad, 1 watt output
h
80-7000
|
100-6000
at
-3
dB
(Dolby
prologic)

FM Section
Tuning coverage for USA / Canada
Tuning coverage for Europe
Usable sensitivity at noise & distortion, S/N 30 dB
75 ohm input
Image rejection at 106 MHz
IF rejection at 90 MHz
Full limiting at -3 dB
50 dB quieting sensitivity at 98 MHz: MONO
STEREO
Distortion at 1 mV input: MONO
STEREO
Signal to noise (S/N) ratio at 1 mV input MONO
STEREO
De-emphasis at 100-12,000 Hz
AM rejection ratio at 100 uV-20 mV input
Search level at 98 MHz
Output voltage at 75 kHz dev. : MONO
1 kHz mod., 1 mV input STEREO
Muting threshold at 98 MHz
Overload THD at 98 MHz, 100 % mod.
at 100 mV RF input
Spurious response at 98 MHz
antenna input 3 pV, 1/21F, 2x1/21F
Capture ratio at 1 mV input
Alternate channel selectivity at 0.1 mV.input
Stereo separation :
at 100 % mod., 1 mV input 1 kHz
10 kHz
Distortion :
at 100 % mod., 1 mV input through IHF Filter MONO
STEREO
Automatic stereo threshold
AM Section
Tuning coverage for USA / Canada
Tuning coverage for Europe
Usable sensitivity 600 kHz, 1010 kHz, 1400 kHz
(603 kHz, 1008 kHz, 1404 kHz for Europe)
at 400 Hz, 30 % mod., S/N=-20 dB
Image rejection at 1400 kHz (1404 kHz for Europe)
IF rejection at 600 kHz (603 kHz for Europe)
AGC figure of merit from 100 mV/m at 1010 kHz
(1008 kHz for Europe)
Distortion at 400 Hz, 30 % mod., 5 mV/m input
IF bandwidth at 6 dB down, 350 2 V/m input
Output voltage at 400 Hz, 30 % mod., 5 mV/m input
Audio response at 5 mV/m input 1 kHz 0 dB,
1010 kHz (1008 kHz for Europe), -6 dB
Selectivity at 10 kHz 350 4V/m input
Signal to noise(S/N) ratio at 1010 kHz
(1008 kHz for Europe) with antenna input 5 mV/m
RF overload 400 Hz 80 % mod., 100 mV input
Search level
MHz
MHz
kHz
kHz
puV/m
dB
dB
d8
%
kHz
mV
Hz
dB
dB
%
pV/m
87.5-107.9
87.50-108.00
43
30
0.35
0.5
6
520-1710
522-1611
Limit
2.0
5-12
200+50
70-1.8000
20
35
- 10
800 +60B
General
Speaker load impedance
Power consumption :
Ne load, (No sig mall i sicoesce 2i250. 15 Mec tatecet aa ds shed te toa hes thea res cance N Neti 2a Stee an ceans ately
1/8 Pmax.
Pmax. (Undistorted output) --
Pmax. (THD 10%)
Pmax. (Undistorted) with outlet --
Dimensions (W x H x D) 440 x 110 x 280 mm
(17-5/16 x 4-11/16 x 11 inch)
Weight (Net)
(16.5 Ibs)
Power Requirment
A: 120 V, 60 Hz for American/Canadian Version ‘
B: 120/220 V, 60/50 Hz for muit-voltage version (switchable)
D: 230 V, 50 Hz German/Gerneral European version
E: 240 V, 50 Hz for UK/Austalian version oa
G: 220 V, 50 Hz for Other Area ;
Notes :
1. Norminal specs represent the design specs. All unit should be able to approximate these some will
exceed and some may drop slight below these specs. Limit specs represent the absolute worst
condition that still might be considered acceptabie; in no case should a unit fail to meet limit specs.
2. This manual is based on the General European(D) standard, and provieds information on regional
circuit modification through the use of alternate schematic diagrams or wiring diagram, and
information on regional component variations through the use of parts lists. Design and
specifications subject to change without notice.

WIRING DIAGRAM
TUNER B'D
4001001010
SPPI
PRUs! Prins
POWER B'D
4005011500
MAIN B'D
4001000900
4001001000
POWER S/W B'D
4001000910
VOLUME 8'D
4001001020
Model No. : RV-4050R

BLOCK DIAGRAM
Model No. : RV-405
PL
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9
10

CIRCUIT DESCRIPTION
1C501: CXP50116-5720 (4-bit CMOS Microprocessor}
1. Pin Configuration
TEST MODE 3 CONTROL
-—> TEST MODE 2 CONTROL
> TEST MODE 1 CONTROL
a
—> CENTER MODE 2 CONTROL
r=)
ST/BY CONTROL
ST/BY LED TUNER MUTE FM/AM STEP 2 OPTION
=0— FM/AM STEP 1 OPTION
£)—e CENTER MODE 1 CONTROL
S—
2) —~»
Q\—-
Cy —e»
Da
rd
ey
G)— TUNER TUNE
G3-—— STEREO
§2-<—— MASTER VOLUME
NJUS701 CHIP ENABLE
PRO-LOGIC MODE CONTROL
FIP
3
6f—e
CENTER
MUTE
DRIVE
SEGMENT
58
9
6$—e
MAIN
MUTE
CXP-50116-5720
}—» M7001 CHIP ENABLE
CONTROL IC DATA
CONTROL IC CLOCK
C7821 DATA MUTE «—({) I—e LOGIC DECK PLAY/PAUSE CONTROL
DIGI-LINK
HEADPHONE
REMOCON
PROTECTION
4)
VIDEO 1
=~
1

2. Key Matrix
3. Block Diagram
KSCAN 0 | KSCAN 1 | KSCAN 2 | KSCAN 3 | KSCAN 4 | KSCANS5 | KSCAN8
PIN 28 PIN 27 PIN 26 PIN 25 PIN 24 PIN 23 PIN 22
KEY INO TUNING
VCR 2 MEMORY
PIN 35
KEY IN 1 SURROUND
TREBLE TV/AUX VCR 2 TAPE
PIN 36 MODE MONITOR
KEY IN 2
ALANCE
PIN 37
@-@
@-©@
S-®
SEGMENT
SEGMENT
adieas
MO;
FORT
SIGNAL
siGNAL
_A/O
@-@
@-@ @-®
@-@
B-@
6-@
Hs"
Boss
RAH
} Sino Je eS
u
[ goat's | wore [rot ¢ | roar] ponte [rer r [vont o [pont w | port]
~ teu. frees see se_frer. Sts
REGISTER
[PROGRAMMABLE = 8:
4. Pin Functions
| Symbol _| Description
16-51 Segment SON EE NE et Output for FIP.
[Mute signal output ta LOvO94 SSCS
| 18 DOLBY Output for driving DOLBY LED.
| 19 | 3-ST Output for driving 3-STEREO LED.
| 20-21 | NC | Not used! (NC pins are always connected to Vdd).
| 22-28 | | T?~TO __| Grid signal output for FIP.
| 29. | INT _| Data input of Ko~Ks for key scan.
| 30-31 | = NC____|_Notused!
Data input of Ko~Ke for key scan.
| 38 | EVC.MU. _| Mute signal output to prevent click noise when operating electronic VOL.
39/40 VIDIMID2 Control data output for selecting VCR1 or VCR2 video signal.
According to each mode, data output is as follows.
[Mobe [vib | vio2 | REMARKS
Weng etc tes al
Poruers | a | a | ai Previous state
% Last memory function is available.
Emitial settings
| 41 | M.VOL.IN1
42 CH. MODE
input for main volume.
Port for settings of PRO-LOGIC and 3-STEREO mode.
According to each mode, data output is as follows.
OTHERS
rockers =u. SEGMENT ®©-@
|
accumuLaTor
|
Se
QuT
Pur
:
448 | MEMORY Fs
x4 = SEGME NT ®-e
STS eS ID, ouTPUT =
BIT DATA TIMER (8) KS g Se-Stt
MEMORY TIMER COUNTER 8 : el
Ee ee OO SERIAL 1/O (@) 12288 x8 BIT
MEMORY
TIMER
Gaxa [timer |
rene]
DISPLAY MEMOR
96X46 BIT
FL TUBE a EXTAL@)
CONTROLLER
ORIVER xTaL @
- TEX &)
tx ®&
S/O
& Siem ob PORTX frorr + }} {| f |
> %®8O@o -
—w ' Or OO
PGPH re og ont S Se 8@
PU,PK OF Reg < 2 zr Sle & @2, >
3 So8 3 32q@ OY®
oO aoa & 2 ¢;@
@@ @O®
Ne) 12
| 43 | NCC Notused!
44 PROT. Signal input for protection.
When "L" is input, it is changed to STAND BY.
(But for first 3 second, PROTECTION Is not checked.)
45 RMC Input for remocon data. (At "L", it is active.)
46 H/P_IN When inserting headphone, “H" is input.
47 D. LINK Input/output for controlling DIGI-LINK.
| 49-50 | CLK/DATA | CLOCK/DATA output for TDA7300, TC9154, LC7821, NJU9701 and LM7001.
51 CE1 Chip enable output for LM7001.
| 52 | _CE2_ _| Chip enable output for TDA7300.
| 53 | CE3 Chip enable output for TC9154. ae
54 CE4 Chip enable output for LC7821.
55 H/P MUTE Output for headphone mute. “H’ is outputed under the following conditions.
1. When the power is on or off.
2. When selecting the input function.
3. When “H" is input to H/P input.
4. When "L" is input to “PROT” of CPU.
5. "-co "mute signal is transferred from the commander.
13

Symbol
MAIN MUTE
Description
Output for main mute. "H” is outputed under the following conditions.
1. When the power is on or off.
2. When “H" is inputted to H/P input.
3. When °L" is inputed to "PROT" of CPU.
4. “-co " mute signal is transferred from the commander.
Output for SURR. mute. “H" is outputed under the following conditions.
1. When the power is on or off.
2. When selecting surround mode.
3. When the test tone mode is on or off or When the channel is
change in the test tone mode.
4. When °H" is inputed to H/P input.
5. When °L° is inputed to "PROT" of CPU.
6.*-c “ mute signal is transferred from the commander.
Output for center mute. "H" is outputed under the following conditions.
1. When the power is on or off.
2. When the center mode is on or off.
3. When selecting center mode.
4, When the test tone mode is on or off or When the channel is
change in the test tone mode.
5. When "L" is inputed to "PROT" of CPU.
6, “-co _“ mute signal is transferred from the commander.
Output for controlling in the surround mode.
- SURROUND MODE PRO 1
PRO-LOGIC, 3-STEREO
SURR. OFF L
| 60 | _CE5__| Chip enable output for NJU9701.
| 61 | PD __| Input for power down. (At “L’, it is active.)
62
M. VOL. IN2 Input for main volume up/down.
57 SURR. MUTE
58 CENTER MUTE
59 PRO
VOL. DOWN VOL UP
ea Sine
IN2
~
STEREO input for lighting the "STEREO" Indicator. {At "L", it is active.)
TUNED input for detecting station during tuning.
If “L" is inputed during tuning, tuning stops at that frequency.
14
[ Pin.No. | Symbot___| Description
ASTEP/F.STEP | According to region, input for selecting the frequency bands and steps
of FM and AM.
Setting are as follows.
| REGION | FREQUENCY STEPS
AMERICA | FM: 87.5~107.9 MHZ
AM: 520-1710 kHz
EUROPE | FM: 87.5~108 MHz
AM: 522~1611 kHz
KOREA FM: 87.5~107.5 MHz | 200 kHz
AM: 522~1611 kHz 9 kHz
T.MUTE Output for tuner mute.
Output for driving STAND BY LED. (At "H', it is active).
69/70
CM1/CM2 Contro! data output for center mode in the DOLBY PRO-LOGIC and
3-STEREO mode.
Setting are as follows.
we a
This pin prevides the ground potential.
Output pin serve for connecting a clock oscillator crystal.
7 Vss
XTAL
~
NS
73 | NC Not used !
74 EXTAL Input pin serve for connecting a clock oscillator crystal.
NC
Vieo This is the power supply pin of the FL controller.
NS3~NS1 Control data output for selecting channel in the test tone mode.
says
77~79
Setting are as follows.
SELECTION NS1 NS2 NS3
TEST TONE OFF
4 : previous state
STAND BY When the power is on, control data output is “H”.
When the power is off, contro! data output is “L”.
{and last memory function is activated.)
18

5. Digital Tuning System Description
FM FRONT-END PACK
2 Se em mony
!
I
|
|
I
'
1
'
I
I
i
'
!
i
1
i
&
!
I
4
16
mz, FM PLL Loop
<==] AM PLL Loop
Low Pass Filter
Q417, 0418
PLL Prescaler
FM IN
1C404
AM IN
FL
Display
1. Equipment Required
¢ AM signal generator
« Oscilloscope
* AC voltmeter
« FM signal generator
¢ Stereo modulator
ALIGNMENT PROCEDURES
+ Audio generator
« Distortion meter
-+ OC voltmeter
« Frequency counter
Note: Remove line cord antenna from FM externa! antenna terminal when aligning.
2. Alignment and Test Points (Tuner P.C. Board)
3. AM IF and RF Alignment
Preparation
g
2
Y
=
y?
;
Se
1. Output of Signai Generator should not be higher than necessary to obtain an optimum output
reading.
2. Signal Generator Modulation : 30%
3. Switch : Press to AM.
Signal
Generator
Frequency
Step
450 kHz
{400 Hz, Mod.}
600 kHz
{400 Hz, Mod.}
1400 kHz
(400 Hz, Mod.)
1000 kHz
(400 Hz, Mod.)
Receiver
Frequency on
the Display
| Place at a non-
interference spot
| around 600 kHz
| 600 kHz
1400 kHz
| 1000 kHz
Equipment
Connection
! Adjustment
i Point
for
AC voltmeter | L402 Maximum
to TAPE OUT , (IFT) reading
jack. |
| L405
Same as | Same as
Step 1. i {ANT Coil) -- Step 1
{
Same as TC401 Same as
Step 1. {ANT Trimmer) Step 1
17
| VR403 Indication on
| (AM ADJ) receiver with
:
output
of
500
pV/m

4. FM IF Alignment
Preparation
1.
Signal
Generator
output
should
be
no
higher
than
necessary
to
obtain
an
optimum
output
reading.
2. Switch : Press to FM.
3. Signal generator deviation : 75 kHz.
4. Be sure to disconnect FM line cord antenna during alignment.
Signat
Generator
Frequency
98.1 MHz
(1 kHz, Mod.)
98.1 MHz
(1 kHz, Mod.)
Receiver
Frequency on
the Dispiay
Equipment
Connection
Distortion L403
meter to (FM IFT)
TAPE OUT jack
Minimum
distortion
Zero reading
on AC voltmeter
5. MPX Alignment
FM Antenna
Terminal (3000)
FM Dummy
with SSG output
level of 6 pV
Tape out
AM *
Signal
Generator
Front-End
FE401
AM
Signal
Generator
Direct Coupling
AM Alignment Connection
as 1250 (112.59) =
O
Zin =500 (750) ® 3 Z out=3002 (Balanced)
O
1502
FM Dummy Antenna to 3002 Antenna terminal of receiver
FM Dummy Antenna
18
FM RAIF and MPX Alignment Connection
Preparation
1. Switch : Press to FM.
2. Tune for 98 MHz on band.
3. Signal Generator output level: 1000 pV.
4. Deviation : 75 kHz, at 100% modulation of composite signal.
5.
Connect
Signal
Generator
to
FM
antenna
terminal
through
FM
dummy
antenna
(300
22).
19
kHz
Signal
Output
.
Step
|
Modulation
Generator
indicator
pein
Level
Frequency
Connection
Setting
VR401
(SEP ADJ)
AC voltmeter reading
should be at least
33 dB below.
AC voltmeter to
TAPE OUT jack
of R channel
Composite to
channel
1 kHz “L" CH.
8% Mod.
VR401
(SEP ADJ)
AC
voltmeter
to
Same
as
Step
3.
TAPE
OUT
jack
of L channel
Composite to
channel
1 kHz “"R® CH.
8% Mod.
if
you
could
not
obtain
-35
dB
readings
in
Steps
3
and
4
(compared
with
Step
2),
readjust
VR401
until
you
obtain
-33
dB
readings
for
both
Steps
3
and
4.
Nominal
is
-43
dB.
19