22.1. IC7001 (MN6627954MA) Servo Processor,Digital Signal
Processor/Digital filter and D/A Converter
22.2. IC7002 (BA5948FPE2) IC 4CH Drive
22.3. IC2801 (C2CBYY000482) System Microprocessor IC
23 Exploded Views
23.1. Cabinet Parts Location
23.2. Deck Mechanism Parts Location (RAA4403-S)
23.3. Packaging
24 Replacement Parts List
68
69
70
72
73
75
76
77
78
79
80
81
83
84
84
85
85
87
87
89
90
91
3
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
1 Safety Precautions
1.1. General Guidelines
1. When servicing, observe the original lead dress. If a short circuit is found, replace all parts which have been overheated or
damaged by the short circuit.
2. After servicing, ensure that all the protective devices such as insulation barriers and insulation papers shields are properly
installed.
3. After servicing, check for leakage current checks to prevent from being exposed to shock hazards.
1.1.1. Leakage Current Cold Check
1. Unplug the AC cord and connect a jumper between the two prongs on the plug.
2. Using an ohmmeter measure the resistance value, between the jumpered AC plug and each expose d metallic cabinet part on
the equipment such as screwheads, connectors, control shafts, etc. When the exposed metallic part has a return path to the
chassis, the reading should be between 1MΩ and 5.2MΩ .
When the exposed metal does not have a return path to the chassis, the reading must be
1.1.2. Leakage Current Hot Check (See Figure 1)
1. Plug the AC cord directly into the AC outlet. Do not use an isolation transformer for this check.
2. Connect a 1.5kΩ, 10 watts resistor, in parallel with a 0.15µF capacitor, between each exposed metallic part on the set and a
good earth ground such as a water pipe, as shown in Figure 1.
3. Use an AC voltmeter, with 1000 ohms/volt or more sensitivity, to measure the potential across the resistor.
4. Check each exposed metallic part, and measure the voltage at each point.
5. Reverse the AC plug in the AC outlet and repeat each of the above measurements.
6. The potential at any point should not exceed 0.75 volts RMS. A leakage current tester (Simpson Model 229 or equivalent) may
be used to make the hot checks, leakage current must not exceed 1/2 milliamp. Should the measurement is out of the limits
specified, there is a possibility of a shock hazard, and the equipment should be repaired and rechecked before it is returned to
the customer.
.
Fig. 1
4
1.2. Caution for AC Mains Lead
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
1.3. Before repair and adjustment
Disconnect AC power, discharge Power Capacitors C5101, C5104, C5171, C5172, C5920 , C5940 and C5950 through a 10Ω,5W
5
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
resistor to ground.
DO NOT SHORT-CIRCUIT DIRECTLY (with a screwdriver blade, for instance), as this may destroy solid state devices.
After repairs are completed, restore power gradually using a variac, to avoid overcurrent.
Current consumption at AC 230 ~ 240V, 50 Hz in NO SIGNAL mode (volume min at CD mode) should be ~ 350mA (For EB only).
Current consumption at AC 230V, 50 Hz in NO SIGNAL mode (volume min at CD mode) should be ~ 350mA (for E/ EG/ EE only).
1.4. Protection Circuitry
The protection circuitry may have operated if either of the following conditions are noticed :
·No sound is heard when the power is turned on.
·Sound stops during a performance.
The function of this circuitry is to prevent circuitry damage if, for example, the positive and negative speaker connection wires are
“shorted”, or if speaker systems with an impedance less than the indicated rated impedance of the amplifier are used.
If this occurs, follow the procedure outlines below:
1. Turn off the power.
2. Determine the cause of the problem and correct it.
3. Turn on the power once again after one minute.
Note :
When the protection circuitry functions, the unit will not operate unless the power is first turned off and then on again.
1.5. Safety Part Information
Safety Parts List:
There are special components used in this equipment which are important for safety.
These parts are marked by
be replaced with manufacturer’s specified parts to prevent shock, fire or other hazards. Do not modify the original design without
permission of manufacturer.
Table 1
Reference No.Part No.Part name & DescriptionRemarks
in the Schematic Diagrams & Replacement Parts List. It is essential that these critical parts should
F1K5D162BLA013FUSE
FP5920K5G702A00009FUSE PROTECTOR
FP5940K5G702Z00004FUSE PROTECT OR
FP5950K5G402A00025FUSE PROTECTOR
JK5950K2AA2B000011JK AC INLET
A2K2CQ2CA00007AC CORDEG/ E/ EE
A2K2CT3CA00004AC CORDEB
2 Prevention of Electro Static Discharge (ESD) to
Electrostatically Sensitive (ES) Devices
Some semiconductor (solid state) devices can be damaged easily by electricity. Such components commonly are called
Electrostatically Sensitive (ES) Devices. Examples of typical ES devices are integrated circuits and some field-effect transistors and
semiconductor “chip” components. The following techniques should be used to help reduce the incidence of component damage
caused by electro static discharge (ESD).
1. Immediately before handlin g any semiconductor component or semiconductor-equiped assembly, drain off any ESD on your
body by touching a known earth ground. Alternatively, obtain and wear a commercially available discharging ESD wrist strap,
which should be removed for potent ial shock reasons prior to applying power to the unit under test.
2. After removing an electrical assembly equiped with ES devices, place the assembly on a conductive surface such as aluminium
foil, to prevent electrostatic charge build up or exposu re of the assembly.
3. Use only a grounded-tip soldering iron to solder or unsolder ES devices.
6
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
4. Use only an anti-static solder remover device. Some solder removal devices not classified as “anti-static (ESD protected)” can
generate electrical charge to damage ES devices.
5. Do not use freon-propelled chemicals. These can generate electrical charges sufficie nt to damage ES devices.
6. Do not remove a replacement ES device from its protective package until immediately before you are ready to install it. (Most
replacement ES devices are packaged with leads electrically shorted together by conductive foam, aluminium foil or
comparable conductive material).
7. Immediately before removing the protective material from the leads of a replacement ES device, touch the protective material
to the chassis or circuit assembly into which the device will be installe d.
Caution
Be sure no power is applied to the chassis or circuit, and observe all other safety precautions.
8. Minimize body motions when handling unpackaged replacement ES devices. (Otherwise harmless motion such as the brushing
together of your clothes fabric or the lifting of your foot from a carpeted floor can generate static electricity (ESD) sufficient to
damage an ES device).
7
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
3 Handling Precautions For Traverse Unit
The laser diode in the traverse unit (with optical pickup) may break down due to potent ial difference caused by the static electricity
of clothes or our human body.
So, be careful of electrostatic breakdown during repair of the traverse unit (with optical pickup).
·Way of handling the traverse unit (with optical pickup)
1. Do not subject the traverse unit (with optical pickup) to static electricity as it is extremely sensitive to electrical shock.
2. To prevent the breakdown of the laser diode, an antistatic shorting pin is inserted into the flexible board (FFC board).
3. Do not to apply excessive stress to the flexible board (FFC board). When removing or connec ting the short pin, finish the job
in as short time as possible.
4. Do not turn the variable resistor for laser power adjustment. (It is pre-adjusted during production time)
Grounding for electrostatic breakdown prevention
1. Human body grounding
Use the anti-static wrist strap to discharge the static electricity from your body.
2. Work table grounding
Put a conductive material (sheet) or steel sheet on the area where the traverse unit (with optical pickup) is place, and ground
the sheet.
Caution :
The static electricity of your clothes will not be grounded through the wrist strap. So, take care not to let your clothes touch the
traverse unit (with optical pickup).
Caution when replacing the Traverse Unit
The traverse unit has a short point shorted with solder to protect the laser diode against electrostatics breakdown. Be sure to
remove the solder from the short point before making connections.
8
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
9
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
4 Precaution of Laser Diode
Caution :
This product utilizes a laser diode with the unit turned "ON", invisible laser radiation is emitted from the pick up lens.
Wavelength : 780 nm
Maximum output radiation power from pick up : 100 µW/VDE
Laser radiation from pick up unit is safety level, but be sure the followings:
1. Do not disassemble the optical pick up unit, since radiation from exposed laser diode is dangerous.
2. Do not adjust the variable resistor on the pick up unit. It was already adjusted.
3. Do not look at the focus lens using optical instruments.
4. Recommend not to look at pick up lens for a long time.
ACHTUNG :
Dieses Produkt enthält eine Laserdiode. Im eingeschalteten Zustand wird unsichtbare Laserstrahlung von der Lasereinheit
abgestrahlt.
Wellenlänge : 780nm
Maximale Strahlungsleistung der Lasereinheit :100 µW/VDE
Die Strahlung an der Lasereinheit ist ungefä hrlich, wenn folgende Punkte beachtet werden:
1. Die Lasereinheit nicht zerlegen, da die Strahlung an der freigelegten Laserdiode gefährlich ist.
2. Den werkseitig justierten Einstellregler der Lasereinhit nicht verstellen.
3. Nicht mit optischen Instrumenten in die Fokussierlinse blicken.
4. Nicht über längere Zeit in die Fokussierlinse blicken.
ADVARSEL: I dette a apparat anvendes laser.
CAUTION!
THIS PRODUCT UTILIZES A LASER.
USE OF CONTROLS OR ADJUSTMENTS OR PERFORMANCE OF PROCEDURES OTHER THAN THOSE SPECIFIED HEREIN MAY RESULT
IN HAZARDOUS RADIATION EXPOSURE.
n Use of caution label
10
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
5 About Lead Free Solder (PbF)
5.1. Service caution based on legal restrictions
5.1.1. General description about Lead Free Solder (PbF)
The lead free solder has been used in the mounting process of all electrical components on the printed circuit boards used for this
equipment in considering the globally environmental conservation.
The normal solder is the alloy of tin (Sn) and lead (Pb). On the other hand, the lead free solder is the alloy mainly consists of tin
(Sn), silver (Ag) and Copper (Cu), and the melting point of the lead free solder is higher approx.30 degrees C (86°F) more than that
of the normal solder.
Definition of PCB Lead Free Solder being used
The letter of “PbF” is printed either foil side or components side on the PCB using the lead free solder.
(See right figure)
Service caution for repair work using Lead Free Solder (PbF)
· The lead free solder has to be used when repairing the equipment for which the lead free solder is used.
(Definition: The letter of “PbF” is printed on the PCB using the lead free solder.)
·To put lead free solder, it should be well molten and mixed with the original lead free solder.
·Remove the remaining lead free solder on the PCB cleanly for soldering of the new IC.
·Since the melting point of the lead free solder is higher than that of the normal lead solder, it takes the longer time to melt
the lead free solder.
· Use the soldering iron (more than 70W) equipped with the temperature control after setting the temperature at 350±30
degrees C (662±86°F).
Recommended Lead Free Solder (Service Parts Route.)
· The following 3 types of lead free solder are available through the service parts route.
RFKZ03D01K-----------(0.3mm 100g Reel)
RFKZ06D01K-----------(0.6mm 100g Reel)
RFKZ10D01K-----------(1.0mm 100g Reel)
Note
* Ingredient: Tin (Sn), 96.5%, Silver (Ag) 3.0%, Copper (Cu) 0.5%, Cobalt (Co) / Germanium (Ge) 0.1 to 0.3%
11
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
6 Accessories
Note: Refer to “Replacement Parts List” (Section 24) for part number.
Remote Control
FM Antenna Wire
AC Cord (For E/ EG/ EE
only)
AC Cord (For EB only)
AM Loop Antenna
12
7 Operating Procedures
7.1. Main Unit Key Buttons Operations
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
7.2. Remote Control Key Buttons Operations
13
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
8 New Features
8.1. Using the Music Port
This feature enables you to enjoy music from a portable audio equipment.
With reference to page 15 of the operating instruction manual.
14
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
9 Self diagnosis and special mode setting
This unit is equipped with functions for checking and inspecting namely: Self-Diagnostic and Test Mode.
9.1. Service Mode Summary Table
The service modes can be activated by pressing various button combination on the main unit and remote control unit. Below is the
summary for the various modes for checking:
Player buttonRemote control button unitApplicationNote
[][4], [7]Entering into Doctor ModeRefer to the section, “9.2
ModeRemote control button unitApplicationNote
In Doctor Mode[], [4]+[7]Display firmware version & EEPROM checksumRefer to the section,
[4]Set for cold start when reset start is executed the next timeRefer to the section, “9.2
[Muting]Clock SettingRefer to the section, “9.2
[0]Tape Eject TestRefer to the section, “9.2
[DIMMER]All segment display for the FLRefer to the section, “9.2
Purpose: To check for microprocessor firmware version and EEPROM checksum (ROM correction).
17
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
Below are the procedures for this mode.
Step 1: Enter into Doctor mode (for more information, refer to section 9.2 on the key operation to enter into this mode.
Step 2: Check for firmware version and EEPROM checksum (By pressing STOP button on main unit followed by “4” and “7” on
remote control).
· W hen entering into DOCTOR MODE, the firmware version and checksum data of EEPROM (if applicable) will appear on FL
display. Below is the information on the EEPROM IC (ROM correction) under 3 possible situations:
1. In the case that the correction point existence data is other than 0 (ie. correction file exists), EEPROM checksum display for
the microprocessor shall be made after calculating checksum by summing up the content of data area from EEPRO M IC.
2. In the case when no EEPRO M IC is installed. It is display as below (no display of checksum data)
3. In cases that the filename is different even though a EEPROM is installed, or no correction file exists, [NG] shall be displayed
(the correction point existence data is set to 0 at this condition).
Note: Microprocessor firmware refers to version number for microprocessor IC located on PANEL P.C.B.. It is subject to change
which would be update d accordingly. ROM correction checksum refers to the HEX code that is displayed upon key buttons pressed
if an EEPROM is loaded in the unit.
9.3. Reliability Test Mode (CRS1 Mechanism)
Below is the process flow chart of ageing for the CD changer unit. (CRS1)
18
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
19
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
9.4. Error code Table Display
Self-Diagnosis Function (refer Section 9.2) provides information on any problems occuring for the unit and its respective
components by display ing the error codes. These error code such as U**, H** and F** are stored in memory and held unless it is
cleared.
The error code is automatically display after entering into self-diagnostic mode.
9.4.1. Error Code Table for Deck Mechanism
20
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
9.4.2. Error Code Table For CD Changer Block
21
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
22
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
23
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
9.4.3. Error Code Table For Power Supply
9.4.4. CRS1 Error Code display
CRS1 Error Code display
1. The errors that occured in CRS1 Mechanism can be recalled and displayed, in the order of the occurence under self-diagnostic
for procedures to enter this mode.
· Only the first 5 errors will be memorized (in backup memory). The subsequence error shall be ignored and not memorize.
For system with EEPROM as memory backup,memory space in EEPROM is neccesary.
2. To display all error code memorized
In CRS1 Self-Diagnostic mode, press [SINGLE CHANGE] to display subsequence error code.
It shall repeat after reaching error no. 5.
e.g.:
[1____IHMS]→ [SINGLE CHANGE]
[2____ITOP]→ [SINGLE CHANGE]
[3____HOME]→ [SINGLE CHANGE]
[4____LOAD]→ [SINGLE CHANGE]
[5_____UDD]→ [SINGLE CHANGE]
3. To clear the error code memory
In CRS1 Self-Diagnostic mode, long press [SINGLE CHANGE] key (2s or more)
24
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
10 Assembling and Disassembling
10.1. Caution
Special Note:
This model uses a new CD changer unit CRS1. In this following section does not contain the necessary disassembly &
assembly information for the CD changer unit (CRS1) except the disasembly & assembly of traverse unit. Kindly refer to the
original service manua l for the CD changer unit. (Order No. MD0509368C0).
“ATTENTION SERVICER”
Some chassis components may have sharp edges. Be careful when disassembling and servicing.
1. This section describes procedures for checking the operation of the major printed circuit boards and replacing the main
components.
2. For reassembly after operation checks or replacement, reverse the respective procedures.
Special reassembly procedures are described only when required.
3. Select items from the following index when checks or replacement are required.
4. Refer to the Parts No. on the page of “Parts Location and Replacement Parts List” (Section 24), if necessary.
Caution:
After replacing of CD Changer Unit, ageing test is necessary. Please confirm operation for CD Changer Unit.
Below is the list of disassembly sections
·Disasse mbly of Top Cabinet
·Disasse mbly of Rear Panel
·Disasse mbly of CD Changer Unit (CRS1)
·Disasse mbly of Main P.C.B.
·Disasse mbly of Transformer P.C.B.
·Disasse mbly of Power P.C.B.
·Disasse mbly of Front Panel Unit
·Disasse mbly of Panel P.C.B.
·Disasse mbly of Tact Switch P.C.B.
·Disasse mbly of Deck Mechanism Unit
·Disasse mbly for Deck P.C.B.
·Disasse mbly of Traverse Unit
·Disasse mbly of Deck Mechanism
·Disasse mbly of Deck Mechanism P.C.B.
·Disasse mbly of cassette lid
·Rectification for tape jam problem
Below shown is part no. of different screws types used:
25
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
10.2. Disassembly flow chart
The following chart is the procedure for disassembling the casing and inside parts for internal inspection when carrying out the
servicing.
To assemble the unit, reverse the steps shown in the chart as below.
26
10.3. Main Parts Location
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
27
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
10.4. Disassembly of Top Cabinet
Step 1 Remove 3 screws on both sides on top cabinet.
Step 2 Remove 5 screws at the rear.
Step 3 Lift the sides of top cabine t outwards.
Step 4 Push the top cabinet backwards to release catches.
Step 5 Remove top cabine t.
10.5. Disassembly of CD Changer Unit (CRS1)
·Follow the (Step 1) - (Step 5) of Item 10.4
Step 1 Remove 1 screw at rear panel.
Step 2 Detach the FFC cables at connectors (CN2801 &
CN2805) on Main P.C.B..
Step 3 Release the claws outwards on both ends.
28
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
Step 4 Lift the CD changer unit upwards to remove it.
· Disasse mbly of Mecha Chassis
10.6. Disassembly of Rear Panel
·Follow the (Step 1) - (Step 5) of Item 10.4
Step 1 Remove 6 screws.
Step 5 Remove 2 screws.
Step 6 Remove the Mecha Chassis.
Note:
For disassembly & assembly of traverse unit, please refer to
section 10.15 of this service manual. Please refer to original
Service Manual for the Disassembly and Assembly of the CD
Changer Unit (CRS1).
Step 2 Detach cable at connector CN2810 on Main P.C.B..
Step 3 Detach FFC cables at connectors (CN2801 & CN2805)
on Main P.C.B..
Step 4 Remove rear panel.
29
SA-AK250E / SA-AK250EB / SA-AK250EG / SA-AK25 0EE
10.7. Disassembly of Main P.C.B.
·Follow the (Step 1) - (Step 5) of Item 10.4
·Follow the (Step 1) - (Step 4) of Item 10.5
·Follow the (Step 1) - (Step 4) of Item 10.6
Step 1 Detach FFC cables at connectors (CN2803 & CN2806)
on Main P.C.B..
Step 2 Remove Main P.C.B..
10.8. Disassembly of Transformer P.C.B.
·Follow the (Step 1) - (Step 5) of Item 10.4
·Follow the (Step 1) - (Step 4) of Item 10.5
·Follow the (Step 1) - (Step 4) of Item 10.6
Step 1 Detach cables at connectors (CN5950 & CN595 1) on
Transformer P.C.B..
Step 2 Remove 3 screws (Mounting screws for transformer to
bottom chassis).
Step 3 Push the Transformer P.C.B. backwards to remove it.
30
Loading...
+ 70 hidden pages
You need points to download manuals.
1 point = 1 manual.
You can buy points or you can get point for every manual you upload.