Jvc RX 212 BK Service Manual

Page 1

RX-21ZBK

JVB
_ SERV'CE MANUAL.

RX-21ZBK

MODEL NO.

I'nllnll I ll"!
\lenr U I." In

Ill/Remote /III
Control Component
Contents
Safety Precautions ........................ 1-2 Adjustment Procedures ................... 1-20
Instruction Book .......................... 1-3 Power Amplifier Adjustment Procedures . . 1-21
Description of quor [03 ,,,,,,,,,,,,,,,,, 1.13 Black Diagrams ......................... 1-22
Internal Block Diagram of Other 103 ..... 1-17 Schematic Diagrams ................. Insertion
Internal Connections of FL Display ....... 1-18 Printed Circuit Boards ............... Insertion
Disassembly Procedures .................. 1-19 Parts List ........................... Insertion
No. 20462
Dec. 1993

Page 2

http : //getMANUAL . com

RX-21ZBK

Safety Precautions

1.The design of this product contains special hardware and many circuits and components
specially for safety purposes. For continued protection, no changes should be made to the
original design unless authorized in writing by the manufacturer. Replacement parts must
be identical to those used in the original circuits. Services should be performed by
qualified personnel only.

2. Alterations of the design or circuitry of the product should not be made. Any design
alterations of the product should not be made. Any design alterations or additions will
void the manufacturer's warranty and will further relieve the manufacture of responsibility
for personal injury or property damage resulting therefrom.

3. Many electrical and mechanical parts in the products have special safety-related
characteristics. These characteristics are often not evident from visual inspection nor can
the protection afforded by them necessarily be obtained by using replacement components
rated for higher voltage, wattage, etc. Replacement parts which have these special safety
characteristics are identified in the Parts List of Service Manual. Electrical components
having such features are identified by shading on the schematics and by (A) on the Parts
List in the Service Manual. The use of a substitute repalcement which does not have the
same safety characteristics as the recommended replacement parts shown in the Parts List of
Service Manual may create shock, fire, or other hazards.

4. The leads in the products are routed and dressed with ties, clamps, tubings, barriers and
the like to be separated from live parts, high temperature parts, moving parts and/or sharp
edges for the prevention of electric shock and fire hazard. When service is required, the
original lead routing and dress should be observed, and it should be confirmed that they
have been returned to normal, after re-assembling.

5. Leakage currnet check (Electrical shock hazard testing)
After re-assembling the product. always perform an isolation check on the exposed metal
parts of the product (antenna terminals, knobs, metal cabinet, screw heads, headphone jack,
contorl shafts, etc.) to be sure the product is safe to operate without danger of electrical
shock.
Do not use a line isolation transformer during this check.

0 Plug the AC line cord directly into the AC outlet. Using a "Leakage Current Tester,
measure the leakage current from each exposed metal parts of the cabinet, particularly
any exposed metal part having a return path to the chassis, to a known good earth
ground. Any leakage current must not exceed 0.5mA AC (r.m.s.).

0 Alternate check method
Plug the AC line cord directly into the AC outlet. Use an AC voltmeter having, 1,000
ohms per volt or more sensitivity in the following manner. Connect a 1.5000 10 W
resistor paralleled by a 0.15 [1F AC-type capacitor between an exposed metal part and a
known good earth ground.

Measure the AC voltage across the resistor @ 64231254353
with the AC voltmeter. ohms/volts. . .
Move the resistor connection to each exposed a °_ °' "09 s3"5""W~)
metal part, particularly any exposed metal part
having a return path to the chassis, and 0.15,); AC Type
meausre the AC voltage across the resistor. -|
Now, reverse the plug in the AC outlet and |-l 5
repeat each measurement. Any voltage Wr- >§;3heeigosed
measured must not exceed 0.75VAC (r.m.s.). 150°91°W metal part.
This corresponds to 0.5 mA AC (r.m.s.). Good earth ground

-Warmng

1. This equipment has been designed and manufactured to meet international safety standards.

2. It is the legal responsibility of the repairer to ensure that these safety standards are
maintained.

. Repairs must be made in accordance with the relevant safety standards.
. it is essential that safety critical components are replaced by approved parts.
5. If mains voltage selector is provided, check setting for local voltage.

ht»

1-2 (No. 20462)

Page 70

FIX-2123K

Packing Materials and Part Numbers 9>d€)bNo.mamm

E308447-001 (BS)
Sheet

Acc essories

E300196-08SB

Envelope E207740-0025M

Packing Pad

FMPK4oo1-001
Sheet

E207740-003SM
Packing Pad

FMPY3002-001 (U, UT)
FMPY3002-002 (EN, EF, G)
FMPY3002-004 (BS)
Packing Case

The Marks for Designated Areas

BS the U.K. EN Scandinavia
EF Continental Europe G ..... Germany
UT Taiwan U ..... UniversalType

No marks indicatesall areas

2-16 (No 20462)

Page 86

RX-ZIZBK

I LC7210(IC102) : PLL Synthesizer

1. The main function descriptions
(1) It makes the local oscillation frequency by the control data from IC401.
(2) Decode the control signal and transmit the signal for receiving conditions.
(3) For the best tuning, count the internal-frequency and transmit the data to IC401.

2. Terminal Layout

3. Block Diagram

F
6
V : 5 E
I Reference Phase Detector I
xm I 24 XDut XI" I Driver Charge Pump 21
c: 2 23 vss xour 24 22
DI 3 22 PDZ
16
ex 4 21 PDI Swallow Counter
FM In 19 i . I
Do 5 20 V01) I 1/16,1/17 4blts :
I
57: s 19 FM-OSC : :
__ I .
TUNED 7 is AM-OSC ' 2'3" Programme .5
STOPIN 3 l7 lFReq Mi 18, D'V'der _l
POWER 9 16 FMIF E
osc to 15 AMIF Universal
'IVIGITO n :4 L_I7V (DE! 2 Shift RegisteraLatch Counter 4117120
if
- - CK 4
FM 12 13 MW D0 5 1
9 10 11 12 13 14 17 7 8
OUTD I Z 3 4 S 6 IND 1N1
4. Pin chtion Description
Pin No. Symbol IIO Functions and Operations
1,24 Xin,xout I/O Crystal oscillator (72MHz).
2 CE I Fix the chip enable to 'H when inputting (DI) and outputting (DC) the serialdatar
3 D1 I Receive the control data from the controller(lC401)
4 CK I This clock is used to synchronize data when transmitting the data of DI and DO,
5 DO 0 Transmit the data from LC7218 to the controller which is synchronized with CL.
6 SYC - Not used.
7 Tuned I Receive the tuned signal from IC104(IA1266A).
8 Stop in - Connect to GND.
9 POWER ~ Connect to GND.
10 QSC - Not used.
11 MONO 0 It is 'H" on FM-monaural, L" on FM-Stereo.
12 FM 0 It is 'L on FM mode
13 MW 0 It is L" on MW mode.
14 LW 0 It is "L" on LW mode.
15 AleF I Universal counter input for AM-IF from IC104(LA1266A).
16 FM-IF I Universal counter input for FM-IF from ICio4(LA1266A),
17 IF REQ O Outputthe "IF-signalrequest" to IC104 when the pin-7 (tuned in) goes to H".
18 AM OSC I Input the local oscillator signal of AM.
19 FM OSC I Input the local oscillator signal of FM
20 VDD - This is a terminal of power supply.
PLL charge pump output:When the local oscillator signal frequency is higher than
21 P01 0 the reference frequency high level signals will output.
When it is lower than the reference frequency, low level signals will output. When
it is same as reference frequency signals, it will be floating,
22 PDZ - Not used
23 V55 -- Connect to GND

1-14 (No. 204623)

SVC

PDl
PDZ

HCYR

LCTR

VDD
V55