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SD-PX15H

2 – 9

DVD-ROM can be upgraded from CD-ROM. The write mode is
entered from the normal mode.

1. When any CD-ROM for version upgrade DVD is detected, the sta-

tus informs that the version upgrade ROM is being read.

When DVD microcomputer is changed to System microcomputer
and byte 24 status data detects 0Fh:

• The TEST Mode is entered by the status reception. (Required to

be internally recognized.)

• The Power button /Function switching is prohibited.

(Power supply is necessary until write is completed.)

• It is prohibited to accept any button input until write is com-

pleted.

• Change the display as follows:

Upper 5 x 7 dots: ROM_

Lower 5 x 7 dots: READING_

2. To expand into RAM, DVD performs read-operation.

3. When reading ends, transmission stops for writing.

(Ignore stoppage of transmission during write.)

When transmission stops, the transmission port receives write
states, which are displayed according to port states.

Upper display section: ROM_

Lower display section: W: ***_

4. To open the DVD/CD door when end of rewrite is detected.

(The DVD status is not relevant since there is no communication.)

5. To close the DVD/CD door, cancel the TEST Mode and reset when

the Power button is pressed.

Signals input from BIA102 are input to the AD conversion IC (ICA101,
ICA201 and ICA301) coupled by “CA101, CA102, CA201, CA202,
CA301 and CA302.

Signals input to the AD conversion ICs (ICA101, ICA201 and ICA301)
are converted into 1-bit signals for differential output. For detailed
description of the conversion into 1-bit signals, refer to the Technical
Manual for SM-SX100 already published.

The 1-bit signals switched at the output ICs (ICA102, ICA202 and
ICA302) are converted into analog signals by passing through the low
pass filter consisting of LA104 to LA104, LA201 to LA204 and LA301
to LA304.

The property of low pass filter is flat up to 20 kHz and attenuated at
approx. 40 kHz by approx. 3 dB.

The 1-bit signals switched at the output ICs (ICA102, ICA202 and
ICA302) are amplified between plus power and GND.

By resistive division, the 1-bit signals pass through 75 k

Ω of NF resis-

tance (RA111 to RA114, RA211 to RA214, RA311 to RA314) and are
fed back to the AD conversion IC (ICA101, ICA201 and ICA301). P-P
voltage at this time is approx. 5 V.

1

L

H

—

No  display

2

H

L

During write

W : S T R

3

H

H

Write ended

W : E N D

4

L

L

Write error

W : E R R

SD-PX15H

2 – 10

1. When power is on, the microcomputers (IC002) installed in this

model continuously monitor the following abnormal operations. If
any abnormality occurs, all power except for the circuit driving
these microcomputers are cut off immediately.

1) An abnormal drop in the regulator output voltage.

(Power cut off immediately without any display when the voltage
falls below approx. 1.5 V.)

2) Excessive output offset of the 1-bit amplifier.

(Power cut off immediately after direct current potential exceeds
approx. 2 V.)

3) Excessive main power supply current of the 1-bit amplifier.

(Power cut off immediately without any display when direct cur-
rent exceeds approx. 5.5 A.)

4) Abnormalities detected in the cooling fan motor and its drive cir-

cuit. (Stop, etc.)

Power cut off after “FAN LOCK” displayed.

2. How the microcomputers judge abnormalities and confirming and

canceling the detection line.

Conditions:

1) Abnormalities detected according to the voltages on pin 91 of

IC002 (PROTECT).

2) An abnormality detected when pulse signals input to pin 26

(FAN LOCK) of IC002 are lost for 5 sec.

3. Confirming and canceling the detection line.

CAUTION: When the above failures 1) and 2) are detected and the

detection lines (PROTECT and FAN LOCK) are discon-
nected, protection of the microcomputer does not work.

If the cause is short circuits of regulators and the detection
lines are disconnected, the parts and PWBs may burn out.
Therefore do not disconnect these lines unless it is clear
that the cause is the failures 1) and 2).

(After a failure, a current is supplied for approx. 0.5 sec-
onds which can be observed with an oscilloscope. It is hard
to observe a current with a tester since rising and falling
edges are steep.)

1) If an abnormal drop in the regulator output voltage is detected,

connect the measuring instrument (the oscillograph, etc.) to the
regulator stabilized output and then turn on the power of the set.

When the output voltage is significantly lower than the stabilized
output voltage shown in the circuit diagram, the regulator itself
and its destination circuit are doubtful.

2) Excessive output offset of the 1-bit amplifier is detected, remove

BIA103 and then turn on the power of the set for normal opera-
tion.

• After repairing, adjust the output offset voltage of the 1-bit

amplifier.

SD-PX15H

3 – 1

Audio

SD-PX15H

Service Manual

SD-PX15H

Market

E

 

Caution on Disassembly

Follow the below-mentioned notes when disassembling the unit and reassembling it, to keep it safe and ensure excellent performance:

1. Take DVD and compact disc out of the unit.

2. Be sure to remove the power supply plug from the wall outlet before starting to disassemble the unit.

3. Take off nylon bands or wire holders where they need to be removed when disassembling the unit. After servicing the unit, be sure to rearrange

the leads where they were before disassembling.

1

Rear Cabinet

1. Screw .................... (A1) x8

10

Fan Motor

1. Screw ...................... (K1) x2

2

Front Cabinet

1. Screw ......................

.....................

(B1) x5

2. Socket

(B2) x2

3

Leg Cabinet

Main Chassis

1. Screw ...................... (C1) x6

4

1. Screw ...................... (D1) x5

4. Screw ...................... (D4) x8
5. Tip ........................... (D5) x1

2. Socket ..................... (D2) x6

2. Socket ..................... (G2) x2

2. Socket ..................... (K2) x1

......................

......................

5

Rear Panel

1. Screw ......................

...............

(E1) x5

2. Flat Cable

(E2) x1

...............

3. Flat Cable

(D3) x2

6

Terminal PWB

1. Screw ...................... (F1) x6
2. Screw

(F2) x2

.....................

3. Socket

(E3) x2

............

2. Shield Case

(H2) x1

......................

......................

3. Screw

(H3) x5

7

Power PWB

1. Screw

(G1) x4

8

1-Bit Amp. PWB

1. Screw

9

DVD Servo PWB

1. Screw .......................
2. Socket ......................
3. Flat Cable .................

(J1) x4
(J2) x3
(J3) x3

11

Display PWB

1. Screw .......................
2. Socket ......................

(L1) x6

(L2) x2

13

DVD Mechanism

1. Screw ......................
2. Screw ......................

(N1) x2
(N2) x4

3. Hook ........................ (N3) x1

14

Switch A/Switch B
PWB

1. Screw ......................
2. Screw ......................

(P1) x4
(P2) x4

15

Volume PWB

1. Knob ........................
2. Nut ..........................

(Q1) x1

3. Screw....................... (Q3) x2

5. Spring ...................... (Q5) x1

4. Volume Holder ......... (Q4) x1

(Q2) x1

12

DSP PWB

1. Screw ..................... (M1) x2
2. Socket .................... (M2) x3

16

LED PWB

1. Hook ........................ (R1) x1

After removing the connector for the optical pickup from the
connector, wrap the conductive aluminium foil around the front end
of the connector so as to protect the optical pickup from electro-
static damage.

(H1) x8

(A1)x8

φ3x8mm

Rear Cabinet

Front Cabinet

(B1)x5

φ2.6x10mm

(C1)x6

φ3x8mm

Front Cabinet

Leg Cabinet

Rear Panel

SD-PX15H

3 – 2

Push the terminal through the round hole with tweezers, etc.
To prevent deformation of the center lock, make sure to push back
the lock section in the arrow direction after removing the terminal.

Main Chassis

Main Chassis

(D4)x8

φ3x8mm

(B2)x2

(D2)x1

(D3)x1

Front Frame

Rear Panel

(D1)x5

φ3x10mm

(D2)x2

(D3)x1

(D2)x1

(E1)x2

φ3x6mm

(F1)x6

φ3x8mm

(E1)x3

φ3x6mm

Rear Panel

(F2)x2

φ3x8mm

(E3)x1

(E2)x1

Terminal PWB

Tuner Unit

Rear Panel

(H1)x2

φ3x6mm

(H1)x4

φ3x8mm

(G1)x4

φ3x8mm

(G2)x1

(G2)x1

(H2)x1

(E3)x1

(D2)x1

(H1)x2

φ3x8mm

(D5)x1

Shield
Plate

Caution

1-Bit Amp. PWB

Main Chassis

Power PWB

(H3)x5

 3x8mm

(K2)x1

(L2)x1

(J2)x1

(J2)x1

(J3)x1

(L2)x1

Display
PWB

Fan
Motor

DVD Servo PWB

DVD Mechanism

DVD
Servo PWB

Front Frame

Display PWB

Pull

Pull