HCD-DP900D - Sony Audio Service Manual (repair manual). Page 3

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Selecting 2 and subsequent items executes respective menus and
outputs the results.
For the contents of each submenu, see “Check Items List”.

General Description of Checking Method

(2-2) Revision

ROM revision number is displayed.
Error: Not detected.
The revision number defined in the source file of ROM
(IC206) is displayed with four digits.

(2-3) ROM Check Sum

Check sum is calculated.
Error: Not detected.
The 8-bit data are added at addresses 0x000F0000 ~
0x002EFFFF of ROM (IC206) and the result is displayed
with 4-digit hexadecimal number. Error is not detected.
Compare the result with the specified value.

(2-4) Model Type

Model code is displayed.
Error: Not detected.
The model code read from EEPROM (IC201) is displayed
with 2-digit hexadecimal number.

Model

Model No.

US and Canadian models

20

E, Mexican and Argentine models

22

AEP, UK and Saudi Arabia models

23

Australian model

24

Malaysia, Singapore, Hong Kong,
Thai and Taiwan models

25

Chinese model

26

(2-5) Region

Region code is displayed.
Error: Not detected.
The region code determined from the model code is dis-
played.

(3-2) Gate Array Check

Data write 

→ read, and accord check

Error 02: Gate array write/read discord
Data 0x00~0xFF are written to the address 0xF of gate array
(IC601), then read and checked if they accord.

(3-3) EEPROM Check

Data write 

→ read, and accord check

Error 03: EEPROM write/read discord
Data 0x9249, 0x2942, 0x4294 are written to addresses
0x00~0xFF of EEPROM (IC201), then read and checked.
Before writing, the data are saved, then after checking, they
are written to restore the contents of EEPROM.

(4-2) Servo DSP Check

Data write 

→ read, and accord check

Error 12: Read data discord
Data 0x9249, 0x2942, 0x4294 are written to the address
0x602 of RAM in the Servo DSP (IC701), then read and
checked.

(4-3) DSP Driver Test

Test signal data 

→ DSP Driver

Error: Not detected.
Caution: Do not conduct this test with a mechanical deck
connected.
The maximum voltage is applied to the Servo Driver IC
(IC801, IC802). If mechanical deck is connected, the mo-
tor and optics could be damaged. Disconnect mechanical
deck following the output message, then enter specified 4-
or 5-digit number from the remote commander, and press
the 

[ENTER]

. The test is conducted only when the input

data accord. Check the output level, then press the 

[NEXT]

to finish the test.
This test is skipped if “All” is selected.

Supplement: How to disconnect mechanical deck
Disconnect flat cables connected to the CN002 and CN003
of MB board. Also, disconnect harness from the CN013 of
MB board.

Caution: Do not conduct this check with a mechanical deck con-

nected.
An access is made to the stream supply and servo con-
trol IC (IC303) and external RAM (IC304) using check
data. If mechanical deck is connected, the motor and
optics could be damaged. This check is also executed
by the “All” menu item.

Supplement: How to disconnect mechanical deck

Disconnect flat cables connected to the CN002 and
CN003 of MB board. Also, disconnect harness from
the CN013 of MB board.

(5-2) ARP Register Check

Data write 

→ read, and accord check

Error 08: ARP register write, and read data discord
Data 0x00 to 0xFF are written to the TMAX register (ad-
dress 0xC6) in ARP (IC303), then they are read and checked.

(5-3) ARP to RAM Data Bus

Data write 

→ read, and accord check

Error 09: ARP 

←→ RAM data bus error

Data 0x0001 to 0x8000 where one bit each is set to 1 are
written to the address 0 of RAM (IC304) connected to the
ARP (IC303) through the bus, then they are read and
checked. In case of discord, written bit pattern and read
data are displayed. If data where multiple bits are 1 are
read, the bits concerned may touch each other. Further, if
data where certain bit is always 1 or 0 regardless of written
data, the line could be disconnected or shorted.