The following check should be performed for the continued protection of the customer and service technician.
LEAKAGE CURRENT CHECK
Before returning the unit to the customer, make sure you make either (1) a leakage current check or (2) a line to chassis
resistance check. If the leakage current exceeds 0.5 milliamps, or if the resistance from chassis to either side of the power
cord is less than 460 kohms, the unit is defective.
LASER RADIATION
Do not stare into beam or view directly with optical instruments, class 3A laser product.
DVM1835
CAUTION
Please heed the points listed below during servicing and inspection.
◎ Heed the cautions!
Spots requiring particular attention when servicing, such as
the cabinet, parts, chassis, etc., have cautions indicated on
labels or seals. Be sure to heed these cautions and the cautions indicated in the handling instructions.
◎ Caution concerning electric shock!
(1) An AC voltage is impressed on this set, so touching inter-
nal metal parts when the set is energized could cause
electric shock. Take care to avoid electric shock, by for example using an isolating transformer and gloves when
servicing while the set is energized, unplugging the power
cord when replacing parts, etc.
(2)There are high voltage parts inside. Handle with extra care
when the set is energized.
◎
Caution concerning disassembly and assembly!
Though great care is taken when manufacturing parts from
sheet metal, there may in some rare cases be burrs on the
edges of parts which could cause injury if fingers are moved
across them. Use gloves to protect your hands.
◎ Only use designated parts!
The set's parts have specific safety properties (fire resistance, voltage resistance, etc.). For replacement parts, be
sure to use parts which have the same properties. In particular, for the important safety parts that are marked ! on wiring
diagrams and parts lists, be sure to use the designated parts.
◎ Be sure to mount parts and arrange the
wires as they were originally!
For safety reasons, some parts use tape, tubes or other insulating materials, and some parts are mounted away from the
surface of printed circuit boards. Care is also taken with the
positions of the wires inside and clamps are used to keep
wires away from heating and high voltage parts, so be sure to
set everything back as it was originally.
◎ Inspect for safety after servicing!
Check that all screws, parts and wires removed or disconnected for servicing have been put back in their original positions, inspect that no parts around the area that has been
serviced have been negatively affected, conduct an insulation
check on the external metal connectors and between the
blades of the power plug, and otherwise check that safety is
ensured.
(Insulation check procedure)
Unplug the power cord from the power outlet, disconnect the
antenna, plugs, etc., and turn the power switch on. Using a
500V insulation resistance tester, check that the insulation resistance between the terminals of the power plug and the externally exposed metal parts (antenna terminal, headphones
terminal, microphone terminal, input terminal, etc.) is 1MΩ or
greater. If it is less, the set must be inspected and repaired.
CAUTION
Many of the electric and structural parts used in the set have
special safety properties. In most cases these properties are
difficult to distinguish by sight, and using replacement parts
with higher ratings (rated power and withstand voltage) does
not necessarily guarantee that safety performance will be preserved. Parts with safety properties are indicated as shown
below on the wiring diagrams and parts lists is this service
manual. Be sure to replace them with parts with the designated part number.
(1) Schematic diagrams ... Indicated by the ! mark.
(2) Parts lists ... Indicated by the ! mark.
Concerning important safety parts
Using parts other than the designated parts
could result in electric shock, fires or other
dangerous situations.
1. All Items are measured without pre-emphasis unless otherwise specified.
2. Power supply: AC 120 V, 60 Hz
3. Load Impedance: 100 kΩ load (Audio Output)
4. Room Ambient: 5 °C - 40 °C
3
DVM1835
Safety Check after Servicing
Examine the area surrounding the repaired location for damage or deterioration. Observe that screws, parts, and
wires have been returned to their original positions. Afterwards, do the following tests and confirm the specified
values to verify compliance with safety standards.
1. Clearance Distance
When replacing primary circuit components, confirm
specified clearance distance (d) and (d’) between
soldered terminals, and between terminals and
surrounding metallic parts. (See Fig. 1)
Table 1: Ratings for selected area
Chassis or Secondary Conductor
Primary Circuit
AC Line VoltageClearance Distance (d), (d’)
120 V≥ 3.2 mm (0.126 inches)
Note: This table is unofficial and for reference only. Be
sure to confirm the precise values.
2. Leakage Current Test
Confirm the specified (or lower) leakage current
between B (earth ground, power cord plug prongs) and
externally exposed accessible parts (RF terminals,
antenna terminals, video and audio input and output
terminals, microphone jacks, earphone jacks, etc.) is
lower than or equal to the specified value in the table
below.
Measuring Method (Power ON):
Insert load Z between B (earth ground, power cord plug
prongs) and exposed accessible parts. Use an AC
voltmeter to measure across the terminals of load Z.
See Fig. 2 and the following table.
d'd
Fig. 1
Exposed Accessible Part
Z
AC Voltmeter
(High Impedance)
Earth Ground
B
Power Cord Plug Prongs
Table 2: Leakage current ratings for selected areas
AC Line VoltageLoad ZLeakage Current (i)Earth Ground (B) to:
120 V
Note: This table is unofficial and for reference only. Be sure to confirm the precise values.
0.15 µF CAP. & 1.5 kΩ RES.
Connected in parallel
i ≤ 0.5 mA PeakExposed accessible parts
4
Fig. 2
STANDARD NOTES FOR SERVICING
DVM1835
Circuit Board Indications
1. The output pin of the 3 pin Regulator ICs is
indicated as shown.
Top View
Out
2. For other ICs, pin 1 and every fifth pin are
indicated as shown.
Pin 1
3. The 1st pin of every male connector is indicated as
shown.
Pin 1
Input
In
Bottom View
5
10
Pb (Lead) Free Solder
When soldering, be sure to use the Pb free solder.
How to Remove / Install Flat Pack-IC
1. Removal
With Hot-Air Flat Pack-IC Desoldering Machine:
1. Prepare the hot-air flat pack-IC desoldering
machine, then apply hot air to the Flat Pack-IC
(about 5 to 6 seconds). (Fig. S-1-1)
Fig. S-1-1
Instructions for Connectors
1. When you connect or disconnect the FFC (Flexible
Foil Connector) cable, be sure to first disconnect
the AC cord.
2. FFC (Flexible Foil Connector) cable should be
inserted parallel into the connector, not at an
angle.
FFC Cable
Connector
CBA
* Be careful to avoid a short circuit.
2. Remove the flat pack-IC with tweezers while
applying the hot air.
3. Bottom of the flat pack-IC is fixed with glue to the
CBA; when removing entire flat pack-IC, first apply
soldering iron to center of the flat pack-IC and heat
up. Then remove (glue will be melted). (Fig. S-1-6)
4. Release the flat pack-IC from the CBA using
tweezers. (Fig. S-1-6)
CAUTION:
1. The Flat Pack-IC shape may differ by models. Use
an appropriate hot-air flat pack-IC desoldering
machine, whose shape matches that of the Flat
Pack-IC.
2. Do not supply hot air to the chip parts around the
flat pack-IC for over 6 seconds because damage
to the chip parts may occur. Put masking tape
around the flat pack-IC to protect other parts from
damage. (Fig. S-1-2)
5
DVM1835
3. The flat pack-IC on the CBA is affixed with glue, so
be careful not to break or damage the foil of each
pin or the solder lands under the IC when
removing it.
Hot-air
Flat Pack-IC
Desoldering
CBA
Masking
Tape
Tweezers
Machine
Flat Pack-IC
Fig. S-1-2
With Soldering Iron:
1. Using desoldering braid, remove the solder from
all pins of the flat pack-IC. When you use solder
flux which is applied to all pins of the flat pack-IC,
you can remove it easily. (Fig. S-1-3)
Flat Pack-IC
2. Lift each lead of the flat pack-IC upward one by
one, using a sharp pin or wire to which solder will
not adhere (iron wire). When heating the pins, use
a fine tip soldering iron or a hot air desoldering
machine. (Fig. S-1-4)
Desoldering Braid
Soldering Iron
Fig. S-1-3
Sharp
Pin
Fine Tip
Soldering Iron
3. Bottom of the flat pack-IC is fixed with glue to the
CBA; when removing entire flat pack-IC, first apply
soldering iron to center of the flat pack-IC and heat
up. Then remove (glue will be melted). (Fig. S-1-6)
4. Release the flat pack-IC from the CBA using
tweezers. (Fig. S-1-6)
Fig. S-1-4
6
DVM1835
With Iron Wire:
1. Using desoldering braid, remove the solder from
all pins of the flat pack-IC. When you use solder
flux which is applied to all pins of the flat pack-IC,
you can remove it easily. (Fig. S-1-3)
2. Affix the wire to a workbench or solid mounting
point, as shown in Fig. S-1-5.
3. While heating the pins using a fine tip soldering
iron or hot air blower, pull up the wire as the solder
melts so as to lift the IC leads from the CBA
contact pads as shown in Fig. S-1-5.
4. Bottom of the flat pack-IC is fixed with glue to the
CBA; when removing entire flat pack-IC, first apply
soldering iron to center of the flat pack-IC and heat
up. Then remove (glue will be melted). (Fig. S-1-6)
5. Release the flat pack-IC from the CBA using
tweezers. (Fig. S-1-6)
Note: When using a soldering iron, care must be
taken to ensure that the flat pack-IC is not
being held by glue. When the flat pack-IC is
removed from the CBA, handle it gently
because it may be damaged if force is applied.
Hot Air Blower
2. Installation
1. Using desoldering braid, remove the solder from
the foil of each pin of the flat pack-IC on the CBA
so you can install a replacement flat pack-IC more
easily.
2. The “●” mark on the flat pack-IC indicates pin 1.
(See Fig. S-1-7.) Be sure this mark matches the 1
on the PCB when positioning for installation. Then
presolder the four corners of the flat pack-IC. (See
Fig. S-1-8.)
3. Solder all pins of the flat pack-IC. Be sure that
none of the pins have solder bridges.
Example :
Pin 1 of the Flat Pack-IC
is indicated by a " " mark.
Fig. S-1-7
To Solid
Mounting Point
CBA
Tweezers
Iron Wire
Soldering Iron
Fig. S-1-5
Fine Tip
Soldering Iron
Flat Pack-IC
or
Presolder
Flat Pack-IC
CBA
Fig. S-1-8
Fig. S-1-6
7
Instructions for Handling Semiconductors
Electrostatic breakdown of the semi-conductors may
occur due to a potential difference caused by
electrostatic charge during unpacking or repair work.
1. Ground for Human Body
Be sure to wear a grounding band (1 MΩ) that is
properly grounded to remove any static electricity that
may be charged on the body.
2. Ground for Workbench
Be sure to place a conductive sheet or copper plate
with proper grounding (1 MΩ) on the workbench or
other surface, where the semi-conductors are to be
placed. Because the static electricity charge on
clothing will not escape through the body grounding
band, be careful to avoid contacting semi-conductors
with your clothing.
DVM1835
<Incorrect>
<Correct>
CBA
Grounding Band
1MΩ
1MΩ
CBA
Conductive Sheet or
Copper Plate
8
CABINET DISASSEMBLY INSTRUCTIONS
DVM1835
1. Disassembly Flowchart
This flowchart indicates the disassembly steps to gain
access to item(s) to be serviced. When reassembling,
follow the steps in reverse order. Bend, route, and
dress the cables as they were originally.
[1] Top Cover
[7] Power SW
CBA
[8] Relay CBA
[9] Sensor CBA
[13] Loading
Pulley
[14] Slide Tray
Gear (B)
[15] Slide Tray
Gear (A)
[16] Motor
Assembly
[17] Switch CBA
[18] Tray
Guide (R)
[6] Function CBA
[2] Front Assembly
[3] Bracket (Top)
[4] Stopper Bracket L, R
[5] Drive
Mechanism
[10] Rear Panel
[11] Tray Guide (L)
[12] Tray Guide
(R) Unit
[19] Changer CBA
[20] AV CBA
[21] Shield Plate
[22] DVD Main CBA Unit
[23] PCB Holder
2. Disassembly Method
ID/
LOC.
No.
PART
Fig.
No.
[1] Top CoverD1 6(S-1)-
Front
[2]
[3]
Assembly
Bracket
(Top)
D2 2(S-2), *8(L-1)1-1
D3 *2(L-2)-
Stopper
[4]
Bracket
D3 4(S-3)-
L, R
REMOVAL
REMOVE/*UNHOOK/
UNLOCK/RELEASE/
UNPLUG/DESOLDER
Note
ID/
LOC.
No.
[5]
PART
Drive
Mechanism
REMOVE/*UNHOOK/
Fig.
UNLOCK/RELEASE/
No.
UNPLUG/DESOLDER
D4,
CN201, CN3001
D5
[6] Function CBAD4 *2(L-3), CN2201-
REMOVAL
Power SW
[7]
CBA
[8] Relay CBAD6
Sensor
[9]
CBA
D4 CN2103, (S-4)-
2(S-5), CN5002,
CN5003, CN5005
D6 2(S-6)-
[10] Rear PanelD7 4(S-7), 11(S-8)-
Tr ay
[11]
Guide (L)
Tr ay
[12]
Guide (R)
Unit
Loading
[13]
Pulley
Slide Tray
[14]
Gear (B)
Slide Tray
[15]
Gear (A)
Motor
[16]
Assembly
Switch
[17]
CBA
Tr ay
[18]
Guide (R)
[19] Changer CBA D10
D8 3(S-9)-
4(S-10), CN3003,
D8
CN3004
D9 (S-11), Belt L-
D9 (S-12), *(P-1)-
D9 -----------
D9 (S-13)-
D9 *2(L-4)-
D9 -----------
CN3102, 2(S-14),
CN3301
6(S-15), CN1601,
[20] AV CBAD10
CN1001, FFC
Clamper
[21] Shield PlateD11 2(S-16), 2(W-1)-
DVD Main
[22]
CBA Unit
D11 2(S-17)-
[23] PCB HolderD11 (S-18)-
↓
(1)
↓
(2)
↓
(3)
↓
(4)
Note
2
2-1
3
4
-
-
-
-
↓
(5)
9
(1): Identification (location) No. of parts in the figures
(2): Name of the part
(3): Figure Number for reference
(4): Identification of parts to be removed, unhooked,
unlocked, released, unplugged, unclamped, or
desoldered.
P=Spring, L=Locking Tab, S=Screw,
CN=Connector
*=Unhook, Unlock, Release, Unplug, or Desolder
e.g. 2(S-2) = two Screws (S-2),
2(L-2) = two Locking Tabs (L-2)
(5): Refer to “Reference Notes.”
Reference Notes
CAUTION 1: Locking Tabs (L-1) are fragile. Be careful
not to break them.
1-1. To release eight Locking Tabs (L-1), first release
five Locking Tabs (A), and then three Locking
Tabs (B). (Fig. D2)
CAUTION 2: Electrostatic breakdown of the laser
diode in the optical system block may occur as a
potential difference caused by electrostatic charge
accumulated on cloth, human body etc., during
unpacking or repair work.
To avoid damage of pickup follow next procedures.
2-1. Short the three short lands of FPC cable with sol-
der before removing the FFC cable (CN201) from
it. If you disconnect the FFC cable (CN201), the
laser diode of pickup will be destroyed. (Fig. D5)
CAUTION 3: When reassembling, confirm the FFC
cable (CN201) is connected completely. Then remove
the solder from the three short lands of FPC cable.
(Fig. D5)
CAUTION 4: Before reinstalling, turn the Slide Tray
Gear (B) fully clockwise. (Fig. D4)
(S-2)
(L-1)
[2] Front Assembly
[4] Stopper Bracket L
(L-2)
(L-1)
(S-3)
(B)
(L-1)
(A)
(S-2)
[3] Bracket (Top)
[4] Stopper Bracket R
(L-2)
DVM1835
(L-1)
(B)
(L-1)
(S-3)
[5] Drive
Mechanism
Fig. D2
(S-3)
Fig. D3
(S-1)
(S-1)
[1] Top Cover
(S-1)
(S-1)
Fig. D1
10
CN2103
(S-4)
[7] Power
SW CBA
CN2201
(L-3)
CN3001
Turn
(L-3)
[6] Function CBA
CN201
Slide Tray
Gear (B)
Fig. D4
DVM1835
Slide
A
Short the three short lands by soldering
Drive Mechanism
B
View for A
OR
Short the three short
lands by soldering
C
[9] Sensor CBA
[10] Rear Panel
(S-6)
CN5005
(S-7)
(S-8)
(S-5)
(S-7)
CN5003
CN5002
[8] Relay
CBA
Fig. D6
(S-8)
(S-7)
(S-8)
(S-7)
Pickup Unit
View for B
View for C
Fig. D5
Fig. D7
11
DVM1835
(S-9)
CN3003
CN3004
[11] Tray Guide (L)
[12] Tray Guide
(R) Unit
(S-10)
Fig. D8
CN3102
(S-14)
(S-15)
CN3301
CN1001
[19] Changer CBA
[21] Shield Plate
FFC
Clamper
(S-15)
(S-14)
(S-15)
CN1601
[20] AV CBA
Fig. D10
[14] Slide Tray Gear (B)
[15] Slide Tray Gear (A)
(S-11)
Belt L
[13] Loading
Pulley
(S-13)
(S-12)
(P-1)
[17] Switch CBA
[18] Tray
Guide (R)
(L-4)
[16] Motor Assembly
Fig. D9
(S-16)
(W-1)
[22]
DVD
Main CBA
Unit
(S-16)
(S-17)
(S-18)
[23] PCB
Holder
12
Fig. D11
FLOW CHART NO.1
The power cannot be turned on.
DVM1835
TROUBLESHOOTING
Is the fuse normal?
Ye s
Is normal state restored when once unplugged
power cord is plugged again after several seconds?
Ye s
Is the EV +9V line voltage normal?
Ye s
Is each voltage of the secondary side normal?
Ye s
When pressing POWER button (SW2201), is the
voltage of 0V supplied to pin(38) of IC3001?
Ye s
Is the voltage of 3.3V supplied to pin(1) of IC3001?
Ye s
Replace IC3001.
FLOW CHART NO.2
The fuse blows out.
Check the presence that the primary component
is leaking or shorted and service it if defective.
No
No
No
No
No
No
See FLOW CHART No.2 <The fuse blows out.>
Check if there is any leak or shor-circuiting on the
primary circuit component, and service it if defective.
(Q1001, Q1003, T1001, D1001, D1002, D1004,
D1005, D1011, C1003, C1005)
Check each rectifying circuit of the secondary circuit
and service it if defective.
Check POWER button (SW2201) and their
periphery, and service it if defective.
Check CHG+3.3V line
See FLOW CHART No.2 <The fuse blows out.>
Check the presence that the rectifying diode or
circuit is shorted in each rectifying circuit of
secondary side, and service it if defective.
and service it if defective.
After servicing, replace the fuse.
FLOW CHART NO.3
When the output voltage fluctuates.
Does the photo coupler circuit on the secondary
side operate normally?
Ye s
Check IC1001, D1012, D1024 and their periphery,
and service it if defective.
FLOW CHART NO.4
When buzz sound can be heard in the vicinity of AV circuit.
Check if there is any short-circuit on the rectifying diode and the circuit in each rectifying circuit of the secondary side
and service it if defective.
FLOW CHART NO.5
-FL is not outputted.
Is -24V voltage supplied to the anode of D1003?
Check if there is any leak or short-circuit
on the loaded circuit, and service it if defective.