Alpine CDA-7832R Service Manual page 7

CDA-7832R
ill. Operating Specifications
various adjustment items from the main microprocessor. Adjustments are performed in response to these
commands by the digital servo LSI. This servo monitor jig receives the signal returned to the main microprocessor
from the digital servo LSI and causes the LED to light or go off. The adjustment condition (of either completed
or not yet completed) of the various adjustment items can be checked using the lighting condition of this LED.
The following test discs are required for the good/fault judgment:
1. A-BEX TCD-721 (6th track - 1.2mm) : Scratch test disc
2. A-BEX TCD-782 : Signal test disc
Measures to be Taken Corresponding to the LED Indication |
4. When a LED other than FAGC or TAGC lights, perform the fault causation analysis using the fault diagnosis chart
according to the LED indication.
i) LED indications Ut: Faulk Unit: OK
SS
aaa
adjustment
Focus offset Corrects the focus error value as an offset.
the presence or absence of a disc.
adjustment value.
adjustment
=e eel
ii) Seven-Segment LED (LPS Value)
Not used since this model is a single CD player. Indication shows "00".
Measurements
A. RF Signal Level Measurement
The main beam of the returning light is received by the photodiode and the output voltage is obtained by current-voltage
conversion of A+B+C+D.
1. Block Diagram
Sample player Oscilloscope
2. Measurement Method
(a). Connect the ground terminal of the oscilloscope VRO (TA2066F (1C1102), pin 20) and measure the RFO signal
(of TA2066F (1C1102), pin 21).
(b). Play the first track of the measurement disc A-BEX TCD-782.
(c). Read the peak-to-peak value of the waveform.
Specification: 1.2+0.3, -0.2V
* When the value is outside of the specification (i.e., not good), check TA2066F (IC1102) and the pick-up.
B. Jitter Measurement
The standard deviation of the pulse width when a trigger is applied to the rising edge of the 3T component of the RF signal.
1. Block Diagram
Sample player
2. Measurement Method
(a). Connect the ground terminal of the jitter meter to VRO (TA2066F (IC 1102), pin 20) and measure the RFO signal
(of TA2066F (1C1102), pin 21).
(b). Play the first track of the measurement disc A-BEX TCD-782.
(c). Read the indicated value of the jitter meter.
Specification: 25nS or less
* When the value is outside of the specification, check TA2066F (IC1102) and the pick-up.