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7-3

5. 24 MHz Adjustment (MB-80 board)

24 MHz is the reference clock to generate 36 MHz clock, and if it is

not adjusted correctly, checking of 36 MHz will result in NG.

Mode E-E

Test point TP022 (512fs)

Instrument Oscilloscope, Frequency counter

Adjusting element CT002

Specification 24576000 ±100Hz

Adjusting method:

1) In the “0” Syscon Diagnosis of the test mode initial menu,

select the DVD mode.

2) Confirm that the waveform at TP022 is normal.

3) Adjust CT002 to attain 24576000 ±100Hz.

7. 36 MHz Lock Check (MB-80 board)

This checks whether 36 MHz is synchronized with reference clock

27 MHz for MPEG system. If it is not locked, the sounds and pic-

tures are not synchronous during MPEG playing or playing is sus-

pended.

Mode E-E

Test point TP021 (PH-COMP)

Instrument Oscilloscope, Frequency counter

Specification 24.0 ±0.01 kHz

Checking method:

1) In the “0” Syscon Diagnosis of the test mode initial menu,

select the DVD mode.

2) Confirm that a rectangular wave at TP021 is locked.

3) Confirm that the frequency is 24.0 ±0.01 kHz.

Figure 7-5

6. 36 MHz Check (MB-80 board)

36 MHz is the reference clock for audio system to play DVD, and if

it is not adjusted correctly, no sound will be generated or sounds

will be distorted.

Mode E-E

Test point TP020 (36 MHz)

Instrument Oscilloscope, Frequency counter

Specification 36864000 ±150 Hz

Checking method:

1) In the “0” Syscon Diagnosis of the test mode initial menu,

select the DVD mode.

2) Confirm that the waveform at TP020 is normal.

3) Confirm that the frequency is 36864000 ±150 Hz.

Figure 7-6

Figure 7-7

8. 16 MHz Check (MB-80 board)

16 MHz is the reference clock for audio system to play CD (includ-

ing video CD), and if it is not adjusted correctly, no sound will be

generated or sounds will be distorted.

Mode E-E

Test point IC770 20 pin

Instrument Oscilloscope, Frequency counter

Specification 16934400 ±75 Hz.

Checking method:

1) Confirm that the waveform at IC770 @º pin is normal.

2) Confirm that the frequency is 16934400 ±75 Hz.

Figure 7-8