Sherwood R-725/RDS User manual

SERVICE MANUAL
R-725/RDS + AV-725
AUDIO/VIDEO PRO-LOGIC RECEIVER
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* A PRODUCT OF AV-725 OMITS ONLY TUNER PART TO R-725
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Sherwood.

SAFETY PRECAUTIONS
WARNING
Before servicing this unit, familiarize yourself with the following precautions:
1. Many electrical and mechanical parts in this exposed metal parts of the cabinet, such as
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 ! 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 leakage current check on the
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 uF 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
(2 resistor and a 0.15 ,1F 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 © per volt or greater sensitivity ,
the reading should not exceed 0.75 V.
AC Outlet
AC Voltmeter
Good earth ground, such as
a water pipe or conduct.
0.15 #F 150V AC
Place the probe on each exposed metalic part.

SPECIFICATIONS
a FRONT AMP SECTION
Measuring methods are based on IHFand IEC standard 268-3.
Measurements conditions, unless otherwise noted :
* Output resistive load : 8 ohms/Both channel driven
* Tone(Bass, Treble), Balance, EQ control : Center Position, Other SW's : OFF.
* Nominal input level : 5 mV for MM, 0.5 mV for MC, 500 mV for general purpose inputs.
* Power figures should be kept minimum 10 min. between 15 and 35 c.
* Terminator : 100 ohm for MC, 1 kohm for MM and general purpose inputs.
* Filter : IHF-A filter * R/O: Rated Output
| NO | DESCRIPTION | __ INPUT FREQ. | REMARK | UNIT LIMIT | NOMINAL
' 4 ‘Input Sensitivity AUX ; 1 KHz mV 200+50 | 200+30
MM | 1 kHz mV 2.5+0.5 | 25+03
"2 |Channel Balance AUX 1 kHz/R/O TO -40dB) dB +3 +2
|
|
1
kHz|-40
TO
-60dB/
dB
+6
+4
(3 |Residual Noise AUX 1 kHz) VOL min. mV A ced ||
| 4 Total Harmonic Distortion AUX (500mV) 20Hz) R/O 1W % <0.2 <0.09
| 1kHz - % <0.2 <0.09
! | |_20Hz : % <0.3 <0.2
| 5 (Continuous Average Power AUX | 20Hz 8ohms WwW 130 132
r at (0.2)% THD 1kHz : Ww | 130 132. |
| | 20Hz WwW 130 132
6 IMD(SMPTE) | AUX(500mvV); 60Hz=4 R/O % <0.2 <0.09
ae 7kHz=1 1w % <0.2 < 0.09
| 7 |S/NRATIO, IHF-A FILTER | AUX(500mvV) 1kHz R/O dB >90 | 3>93 |
MM(5mvV) 1kHz R/O dB >68 2i2 |
| 8 |Channel Separation AUX(500mvV) 100Hz| R/O -3dB dB >45 >55
1kHz . dB >45 > 55
10kHz| . dB >40 >45
{ 9 |Function Crosstalk CDSAUX , 1/10 kHz 7 dB >60/40 | >65/45
| ; AUX->MM 1/10 kHz : dB > 60/40 >65/45 |
| MM ->AUX | 1/10 kHz | : | dB > 60/40 > 65/65 |
; 10 |Frequency Response (-3dB) | AUX(500mvV) Iw i{Hz~kHz;} 20~50 10~6)
11 | Tone Control, +10dB AUX 100Hz | 1Ww dB +10+2 +1041 |
[| | 10kHz 1W dB | +10+2 | +1021
: 12 |Subwoofer Out sub-vol +6dB [AUX(200mvV) | 1kHz | M-Vol Max Vv | 2+0.5 2+0.3
| 13 |Phono Equalization PHONO 100Hz | TAPE OUT dB RIAA+1.5 RIAA1
10kHz i dB | RIAA+1.5| RIAA+1
; 14 |Input Overload at 0.5% THD il MM 1kHz TAPE OUT mV >120 > 14¢
| 15 DIN Power at 1% THD AUX __tkHZ | R/O W > 135 > 14(
' 16 |Muting Level AUX(500mV); 1kHz R/O dB >60 >65
~@ REAR AMP SECTION
Measurements conditions : Input level 300mV, Rear level maz., Master volume adj. delay time 20ms
| NO DESCRIPTION INPUT FREQ. REMARK | UNIT LIMIT | NOMINAL
' 4 |Power Output 0.7% THD AUX | 1kHz | 80hms Ww >50 >52
"2 Total Harmonic Distortion AUX | _1kHz 1W % | <1 <0.7
_ 3 |SIN Ratio DOLBY AUX _| __R/O dB} 55 >63
‘THF-A Filter STADIUM AUX | : dB >55 | 263
! THEATER AUX i : dB >55 | >63
ose HALL AUX : dB >50 | 363
4 | Frequency Response AUX | 1kHz | 1W Hz~kHz,| 100~6 80~7
‘at+3dB
(ONLY
DOLBY)
|
AUX
|
;

« CENTER AMP SECTION
Measurements conditions : Input level 300mV, WIDE mode Center level max., Master volume adj.
NO DESCRIPTION | INPUT | FREQ. REMARK ! UNIT | LIMIT | NOMINAL |
' 1 |Power Output at 0.3% THD AUX | IkHz Bohms | W | _2130 > 132
2_|Total Harmonic Distortion AUX |__1kHz_ 1W % | <03 <0.2 |
3 ‘S/N Ratio, IHF-A Filter AUX | R/O dB >73 >78
4 |Frequency Response | |
IDOLBY MODE NORMAL AUX 1wW iHz~kHz) _120~20 | 100~30 |
WIDE AUX 1wW /Hz~kHz} 60~20 40~30 |
@ VIDEO SECTION
NO | DESCRIPTION "INPUT FREQ. REMARK | UNIT | LIMIT | NOMINAL |
| 1 |Output Level at 750hms | VCR1(1Vp-p)|_1MHz | Vp-p | 140.2) 1401 |
| 2 Frequency Response " 1MHz 'Hz~MHz DC~6 | DC~63 |
3 |S/N Ratio : 4MHz | dB | 40 | 45 |
4 |Crosstalk " 1MHz 7B 40 45. |
a AM SECTION
Measuring methods in confirmity with IEC standard 315
Measurements condition AM - MW
* Radio frequency = 1000/999kHz, Audio frequency = 400Hz
“LM: Radio frequency = 207kHz, Audio Frequency = 400Hz
* Reference level = 5 mV/m, 10 mV/m on 50 ohms
* Test point : MW TP1=594 kHz, TP2=999 kHz, TP3=1404 kHz (USA Version)
“ Test point : MW TP1=600 kHz, TP2=1000 kHz, TP3=1400 kHz (Europe Version)
* Test point : LW TP1=162 kHz, TP2=207 kHz, TP3=1404 kHz (USA Version)
* Test point : LW TP1=600 kHz, TP2=1000 kHz, TP3=1400 kHz (Europe Version)
NO) DESCRIPTION VERSION | UNIT; LIMIT | NOMINAL |
| 1 |Tuning Cover Range LOW~HIGH USA | kHz | §20~1710
| EUROPE | kHz | 522~1611
iSTEP USA si kHz 10
= EUROPE kHz __ 9
| 2 \Usable Sensitivity MW TP1 USA | uv/im , <800 |; <500
| TP2 uVim | <800 <500
i TP3 uvim | <800 = <500 |
| MW TP1 EUROPE uvVim <800 , <500 |
TP2 uV/m <800 <500 |
| TP3 uV/im | <800 <500 |
3 "SIN Ratio MW USA dB, 235 | >40
EUROPE dB >40 | >45
4 ‘Total Harmonic Distortion USA % <2 <1.0
| EUROPE % <1.5 <10 |
5 Over Load Distortion 5 mV_80 % MOD ty = 10 <5 |
6 (Frequency Response at - 6 dB MW | | Hz | 100~2K 80~2.2K |
7 |Selectivity 10 kHz/ 9 kHz MW | dB | 320 >25
| 8 AGC Figure of Merit dB | 550 355 |
| 9 ‘Image Rejection MW = TP3 i | dB} 330 335 |
| 10 |Whistle Modulation Input=1mV/m_ 21F | | % <15 — < 10 |
| 11 |Auto Stop Level MW uV/m_ | 800( + 6dB); 800( +5dB)
| 12 Tuned Level MW __uV/m_ | 800(+6dB) 800(+ 5dB),
_ 13 ‘Output Level mV 165+50 165+30 |

a FM SECTION
Measuring methods in confirmity with IEC standard 315
Measurements condition FM : Radio frequency = 98.1 MHz, Audio frequency = 1kHz
* Reference level = 1mV on ( 75 ohms, 300 ohms )
* Deviation : MONO = +75kHz, Stereo = +67.5kHz +7.5kHz (USA Version)
MONO = +40kHz, Stereo = +40kHz +7.5kHz (Europe Version)
* Test Point : TP 1 = 90.14MHz, TP2 = 98.1MHz, TP 3 = 106.1MHz
* Filter = B.P.F at STEREO
~NO: DESCRIPTION VERSION | UNIT LIMIT | NOMINAL |
|
1
Tuning
Renge
LOW~HIGH
|
USA
|
MHz
|
87.5
~
107.9
oa Europe | 87.5 ~ 108.0
‘Step AUTO/Man USA kHz ; 200
fo Europe 100/50
| 2 |Usable Sensitivity TP 1 i USA | GBF | <17.2 <14.2 |
SIN
=
30
dB
TP
2
|
dBf
;
<17.2
<14.2
|
TP 3 | | dBf <17.2 <14.2 |
‘S/N = 26 dB TP 1 Europe qBf |§ <202 (| <17.2
TP2 | dB | <20.2 <17.2
| TP 3 | =a dBf <20.2 <17.2
3
Full
Limiting
Sense
Output
=
-3
dB
|
USA
|
dBf
<152
|
<122
| Europe | dBf | <20.2 <17.2_|
| 4 ‘Auto Stop Level 2 dBf | 31.245 | 31.24+3 |
|
5
Auto
Error
USA
1
KHz
|
0
64200
|
425
1 | |___ Europe kHz +15 | +20
6 S/N Ratio MONO | dB >64 >68
| STEREO dB 260 | =64 |
|
7
‘Total
Harmonic
Distortion
MONO
%
<05
|
<O03
|
| STEREO | | % | <08 <O.5 |
_
8
'50
dB
Quietion
Sensitivity
MONO
|
USA
|
GBF
|
<23.2
|
<202
|
| STEREO | dBf § <48.3 | <453 |
46 dB Quietion Sensitivity MONO ___ Europe qBf = <232 <202 |
| STEREO | ___OBf <483 <453
| 9 |Channel Separation 100 H2z | | dB 235 i >40
—_ 1 kHz dB 6340, 345
oa 10 kHz | | dB | 230 | 235
10 |Frequency Response at +1.5 dB | I Hz 20~12.5 10~14
| 11 Spurious Response | USA | dB | 270 |, >80 |:
po 4 Europe | dB > 80: >90 |
| 12 |IF Rejection TP 1 | | 4B | =70 >80 |
| 13 Image Rejection TP 3 USA dB 386560) | «0365
a
___Europe
|
OB
|
=70
|
>80
|
| 14 :AM rejection Ratio | ; dB >50 i: 355 |
15 _ Capture Ratio {__ dB 22.5.) 22
|
46
.Alternative
CH
Selectivity
+400
kHz
|
dB
|
245
|
>860
' 17 ‘Output Level MONO | mV | 500+150 | 50+100 |
|
48
[RDS
Sensitivity
(Europe
|
dBf
|
<40.2
|
«382
|
w= GENERAL
Power
consumption
----------
rrr
rrr
crt
rte
r
rer
ctee
USA/Canada
:
4.5A,
Europe
1
100W
Power
Supplies
+--+
=s<se-ise
snes
e
neste
es
ee
Seite
reese
s
USA/Canada
:
AC
120V,
60Hz
Europe : AC 230v, 5OHz
Dimensions (WxHxD) -----++--0 rrr rrr rrr cre rrr retest cress 440 x 140x380 mm
17-5/16 x 5-1/2 x 14-1546 inchs
Weight (Net)- --------------2-e eer e rte rere eee renee! 15.9 kg (31.3 3 Ibs)

CIRCUIT DESCRIPTION
1C301 : CXP82840
1. Pin Description
GRID SEGMENT SEGMENT
NromwmDnwonrtrranr oo
SBE6SESSOGRRLHTHLSAKAAe See
LLEEEEE LET EILE LETT Ty
{oXOSOBLOTIOELOSIOAOSIO2O NOVES/BEE7(BEKB5)/041ESE216')
G7 O-— @0)—+O
GRID eae ae ae
NC O— (78)—+O
POWER DOWN O—+ 77)—+O
RDS CHECK O—+ (764) —+O
RDS START O—+(6) 75)—-O
ENCODER
UP
O—+(7)
?4)—+O
REMOTE O—+(8) 73—+O
ENCODER
DOWN
O—+(9)
?3—-O
NC O—(10) ?71)—+O
NC O—(11) (70)—+O
MAIN - MUTE O-«—(12) 69)—+-O
AMP DATA O=—(13) 68)—+O
AMP CLOCK O-—(14) 67)—-O
NC O—(15) CXP-82840 66)—+O
INt
O—+(6)
63—-O
kevin
|
N2
O-*G2
64)—-O
IN3 O—(18) 63)—+O
IN4 O—+(19) 62—-O
DIGI- LINK O--+(0) 61\—+O
MODEL-OPTION O—+(21) )
RDS
CLOCK
O-—(22)
69—-O
RDS
DATA
O-—(23)
G3)—+O
CENTER- MUTE O-—(24) 67)—+O
REAR MUTE O-—@5) 66)—+O
7001- DATA O«—(26) 65)—+O
7001- CLOCK O+—@7) 64)—+O
VREF O—@8) O
SLEEP O—+(29) 62)—+O
PROTECT
O—+(0)
6)—-O
ae eee: Pecueusee:
OomzZzana ZQr QoQoaqonanazauww
eeOnSee 2 2228858856
wwf OE uw Or 20Ra0
rs
c
xX
Oa
q
aa
Sy
>
QB
tw Ww o OF
Zu 0a - Oo
ae :
“”
=
fan}
=>
Yn
P19
P18
P17
P16
P15
P14
P13
P12
pir |
eo |e
P9 W
P8
P7
P6
P5
P4
P3
p2
Py
ST-BY RELAY
NC
TUNER MUTE
C7821 C.E
TC 9299 C.E
LM 7001 C.E
VCR2 F/R
AMP MUTE
NC
CINEMA BASS
4094A C.E

2. Input/Output Terminal Functions
G2/G1 Grid signal output for FIP.
POWER DOWN | Input for power down(Active low).
RDS CHECK Input for RDS check.
RDS START Input for RDS start.
ENC
UP/DOWN
|
Input
for
Encoder
up
and
down.
NC
REMOCON
Input
for
remote
control
signal.
(Active
low).
Puc
[hte
Output for main mute.
1/2
3
4
5
7/19
10/11
12 MAIN MUTE
Output is low level under the following conditions.
1. When power is turned on or off.
2. When function is changed.
3. When MONO or STEREO is changed.
4. When Low level is inputed to "PROTECTION" port of CPU.
5. When mute signal is received from the commander.
Output datasignal to MC14094, LC7821, LC7822 and TC9299.
Output clock signal to MC14094, LC7821, LC7822 and TC9299.
Input for selecting Model. ('L'>R525, 'H'R-725, AV725)
C-MUTE Output for center mute.
Output is low level under the following conditions.
1
1
2
2
2
3
4
15
0
1
2
23
24
1. When power is turned on or off.
2. When center mode is on or off.
3. When center mode is switched.

C-MUTE 4. When test tone mode is on or off, When the channels is changed
S-MUTE
the test tone mode.
5. When Low level is inputed to "PROTECTION" of CPU.
6. When mute signal is received from the commander.
24
5
2 Output for surround mute.
Output is low level under the following conditions.
1. When power is turned on or off.
2. When surround mode is on or off.
. When test tone mode is on or off, When the channels is changed
oo
the test tone mode.
. When delay time is changed.
5. When Low level is inputed to "PROTECTION" of CPU.
6. When mute signal is received from the commander.
26/27 | 7001-DATA/CLK | DATA/CLOCK Singnal output for LM7001.
AV REF Referance voltage of analog A/D converter.
2
2 SLEEP OPTION | Input for selecting function. ('H'—St-by, 'L'-Sleep.)
PROTECTION Signal input for protection wher low level is inputed, it ischinged to
STAND-BY mode.
STEREO Input for lighting the ST(Stereo), Inaicator(Active low).
S-METER Input signal level of tuner.
SUBWOOFER inplut for selecting subwoofer, when high level is inputed subwoofer volume
OPTION is operates.
35 STEP According to region, input for selecting the frequency bands and steps for
FM and AM
Settings are as follows
FREQUENCY BAND _—STEP
USA/ FM: 87.5 ~ 107.9 MHz 200 kHz
AM: 520 ~ 1710 kHz 10 kHz
EUROPE | FM: 87.5~108 MHz 50 kHz
aaa AM: 522 ~ 1611 kHz 9 kHz
KOREA FM: 87.5 ~ 107.9 MHz 200 kHz
eee AM: 522 ~ 1611 kHz 9 kHz
Input for selecting set. (65V--RDS Receiver, 2.5V—+Amp, 0V—Receiver)
Input for resetting CPU. (Active high)
39/40 Input/Output for cystal oscillator.
41 Ground.
8
AS)
30
31
32
33
34
36
37
38

nc [NetwesSC—“S*s*s*~“‘“S~*Ss*s—‘“—s~‘s~s~S~*Y
D
F
| == vDD | Power supply of CPU(+5V)
G
V ;
v
CE( :
E( ideo).
42
43
44
45
46/47
48
49
50
51
52
53
D
D
L
)
4
AMP-MUTE
When
the
power
is
on,
contro!
data
output
is
high
after
3
seconds.
nn
When the power is off, control data output is "L".
VCR2 OPTION Output signal for VCR2 Inputs. (‘H'-Front, 'L'-Rear)
CE(7001) LM7001 chip enable.
CE(9299) TC9299 chip enable. (Surr-Subwoofer Trim)
CE(7821 LC7821 chip enable. (Function select)
N
Output is high level under the following conditions.
1. When power is turned on or off.
2. When tuner band is changed.
3. When tuning up or down button is pressed.
4. When preset button is pressed.
5. When displayed preset number is changed during memory scan.
6. When Low lever is inputed to "PROTECTION" of CPU.
T-MUTE Output for tuner mute.
)
ST-BY Output for driving power relay. (Active high)
D
55
56
57
58
59
7. When mute signal is received from the commander.
61 vi
90-94 $28 - $32 Segment 28 - Segment 32
95-100 G8-G3 Grid 1 - Grid 5.

3. Block Diagram
@ XTAL
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z
CPU
CORE
SYSTEM
CONTROL|<>|
|”
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|
@-@
GOIAG~G15/A15
Kis]
5
(3
|
' FOP z 2 Ks! PBO~PB7
@-@ Ate-A23 KB] CONTROLLER 5 al’! @-@
m~
|
t
as
PH7/A24~PD7/ASS K32_| g 3 :
Cr Eada Cea eee ee aes 4 RAM = yond
a
Pco/KRo~PC7/KR7 [8 3 | 32K / 40K BYTES 1536 BYTES |S} |
'
r
ey
a
PES/PWH oe-—| 14 BIT PWM GENERATOR |<>> m & CB poo-po7
1 ] @-
PE4/RMC o——| —
1 P| mote
eee
|
or
® eecee o> SERIAL i , rece
——
INTERFACE
|
FIFO
|
"O-
@rraneees So UNITO_! PRESCALER/ S2KHZ EL.
. ‘ TIME BASE TIMER | | TIMER /COUNTER SE @N! pro-pe7
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PBE/SI1
Pinion
Mea
aren
eB
AB
ve
@
pp7/sot
—
SERIAL
INTERFACE
UNIT
4
|)
1
'
@-®@
@)
PBS/SCK1
(3
|
‘
'
yy
@® PEOANTO/ECO 8 BIT TIMER / COUNTER 0 Ky a oo
: 8 BIT TIMER 1 ; i
' '
@
SPENTO
oe
[46
BIT_
CAPTURE
kg
bes
Le
er
©
PELANT2ECI
TIMER
/
COUNTER
2
LI
|
BEI DS TTT ;
beer wee ee = ee ee ee ee ee
4. Key Matrix
Key Scan 2] Key Scan 3} Key Scan 4| Key Scan 5 | Key Scan 6 | Key Scan 7| Key Scan 8 | Key Scan 9| Key Scani0}Key Scan11
Pin 80 Pin 79 Pin 78 Pin 77 Pin 76 Pin 74
; F Station [Center Level Tuning Memory
ae 7 a | sain Pearse] owe [Tare [hemor | 7 | «| seo | semen | seen |
: : (Center Leve PTY FM Tuning i
F : Tape2, , Rear Level
F : Video Center Cinema Rear Level :
ree " au em | rie aie eau