Nakamichi SoundSpace 9, Service Manual

Page: 14 / 55

1-9
SS-9 Main Unit Section
STEP ITEM SIGNAL OUTPUT ADJUST- REMARKS
SOURCE CONNECTION MENT
1 Laser Current ABEX Test Disc DC Voltmeter —
Check TCD-784 across R101
on CD P.C.B.
1. Turn ON the power and load a test disc.
(To load the test disc, press the Open/Close button
of the CD Player.)
2. Play back the test disc and calculate the current
flowing into R101 on the CD P.C.B. Ass'y from the
following formula.
Voltmeter Value
I(Measured) = = oo.o mA
R101 (10 Ohms)
Example:
510.3 (mV)
I(Measured) = = 51.03 mA
10 (ohms)
3. Check that the I(Measured) obtained in 2 and the
rated current value (IOP) shown on the label are
almost the same.
[How to read IOP on the label]
The shaded "OOO" on the label shows the IOP.
If "OOO" is 475, the IOP is 47.5mA.
NOTE: The calculated current (I(Measured))
should be in a range of 30 to 60 mA. If the
value is large, the pickup will be defective.
4. Stop the test disc.
2.3. Electrical checks for CD Player
Note: Do the same check for CD Player Nos. 1 to 3.
KSS-540A
IOP(oo.omA)
Laser Pickup
KSS-540A
1. Play back the first track of the test disc.
2. Be sure that the peak-to-peak value of the EFM
waveform is approx. 1V.
Oscilloscope Setting:
AC Mode, 0.2 V/div, 0.5
µ
s/div
3. Stop the test disc and eject it.
2 EFM Signal ABEX Test Disc Oscilloscope —
Adjustment TCD-784 between
pin 1 of TP101
and GND
on CD P.C.B.
Approx. 1Vp-p