ICD-37, ICD-57, ICD-67 - Sony Audio Service Manual (repair manual). Page 2

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5-1. Block Diagram ................................................................

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5-2. Printed Wiring Board ......................................................

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5-3. Schematic Diagram ......................................................... 11
5-4. IC Pin Function Description ........................................... 17

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The BAD-BLOCK check* must be executed, when the flash
memory (IC702) in this set was replaced.
The set will not operation normally, unless this check is finished.

* The BAD-BLOCK check detects an area (bad-block) in the flash
memory where data validity cannot be guaranteed, and saves this
information in the TOC-AREA so that a bad-block is not used.

BAD-BLOCK check Procedure:
1. Apply 1.5 V from regulated power supply to the battery termi-

nals.

2. Once the power is supplied, the check starts and then proceeds

for approx. 25 (ICD-37)/45 (ICD-57)/87 (ICD-67) seconds.
(Be sure to keep applying the power and pin yj or TP13 (green)/
Pin yh or TP14 (red) signal “H” during the check)
* Green/red LED of 

[OPR]

 indicator don't light up, therefore

it cannot be seen visually. Check the signal of pin yh , yj or
TP13, 14.

3. When the check completes, the result is shown as follows.

OK: Pin yh or TP14 signal “L” (Pin yj or TP13 Signal “H”)
NG: Pin yj or TP13 signal “H” (Pin yh or TP14 signal “L”)

4. In case of OK, press the 

[STOP]

 button.

• In case of NG, check system controller IC (IC701), flash memory IC

(IC702) and the peripheral circuit. (Particularly, check carefully the sol-
dering of the flash memory)

• After finishing the BAD-BLOCK check, assemble the set, load the dry

battery, and confirm if the set operates normally.

• Never reuse a disconnected chip component.
• Notice that the minus side of a tantalum capacitor may be dam-

aged by heat.

• Keep the temperature of the soldering iron around 270 ˚C dur-

ing repairing.

• Do not touch the soldering iron on the same conductor of the

circuit board. (within 3 times)

• Be careful not to apply force on the conductor when soldering

or unsoldering.