Advertisement
SECTION 4
ELECTRICAL ADJUSTMENTS
4-1. CAUTION ON LASER DIODE EMITTING
CONFIRMATION
Never look the laser diode emission from right above when adjusting.
It may cause loss of eyesight.
4-2. NOTE ON MiniDisc device (KMS-140B)
HANDLING
The laser diode within the optical pickup is extremely subjected to
electrostatic destruction. So, the laser tap on the flexible board should
be bridge soldering when handling. Furthermore, take fully
measurements against the electrostatic destruction. Take care of
handling the flexible board because it can be damaged.
oy
svar]
After replacing the MiniDisc
device, perform adjustment and
confirmation as follows.
*
Temperature compensation offset adjustment
¢
Laser power adjustment
*
MO groove traverse adjustment
¢
E-F balance adjustment
*
MO pit traverse adjustment
*
CD RF level adjustment
*
CD traverse adjustment
*
Error rate confirmation
4-3. NOTE ON ADJUSTMENT
1) Perform adjustment in the test mode.
Release the test mode after adjustment.
2) Adjustment should be performed in order described.
3) Use jigs and measurement tools described below.
*«
CD test disc TGYS-1
(Part No.: 4-959-188-01)
«
Continued recorded disc PTDM-1
(Part No.: J-2501-054-A)
¢
Laser power meter LPM-8001
(Part No.: J-2501-046-A)
¢
Error rate counter MDPE-1
(Part No.: J-2501-047-A)
¢
Oscilloscope (band more than 40 MQ, Calibrate the probe before
performing the measurement.)
*
Digital volt meter
¢
Temperature meter
4-4. OFFSET ADJUSTMENT
Note: This adjustment should be performed immediately after
setting the test mode. Performing other adjustments switch
the operation mode, and the correct adjustment can not be
performed.
1) Temperature compensation offset adjustment
Connection:
;
Oscilloscope
RF/SERVO board
TP (TEMPO) o«—______—-© +
TP (VC) o<——_——_0—
Adjustment method:
1. Connect the oscilloscope to TP (TEMPO) and TP (VC) on the
RF/SERVO board.
2. Adjust RV208 on the RF/SERVO board so that the reading on
the oscilloscope meets the specification.
Specification: 0£20mV (25°C)
+8.4mV/°C (Increased by 8.4mV with every
increasing temperature by 1°C)
2) Focus bias offset adjustment
Connection:
;
Oscilloscope
RF/SERVO board
TP (FEO) o_o
+
Ly
Adjustment method:
1. Connect the oscilloscope to TP (FEO) on the RF/SERVO board.
2.
Adjust RV206 on the RF/SERVO board so that the reading on
the oscilloscope becomes —230430mV.
3) FOK offset adjustment
Connection:
;
Oscilloscope
RF/SERVO board
TP (ABCD) o@————__o +.
Adjustment method:
Advertisement
