JVC RC-X3 - Page 16

RC-X3 B/E/G
m@ CD Player Adjustment
Fromt
VRSO3
VCO Adj
TRACKING Gm. em nee ne ee ee
Gain Adj
evrso5 VRSO!
Tracking Error
(Offset) Adj
Fig. 8-4
CD Unit
A ‘‘CD unit’ is an Ass'y combination of the CD mechanism (KSM-150BA-A part no. KSM-150B-AJRS) and the CD board
(VMW 1176). Service personnel! call this Ass’y a CD unit.
(1) When a stable DC power source is used, connect the GND of FW4 (6) and FW4 (2);
(2) The audio output’s load resistance is 47 kQ.
Monitoring from the CD OUT terminal is also possible.
(3) When a disc is to be inserted, first remove the set’s magnet clamper.
(4) Short circuit the S609 OPEN/CLOSE switch.
When CN601 GQ) @) are shorted, TOC reading will begin.
Adjustment procedure
(1) VCO free run adjustment (IF VCO free run adjustment is improper, TOC cannot be read.)
@ Adjustment tool: Frequency counter
1) Short circuit have TP7 (IC501 6) terminal = ASY) and TP6 (D-GND).
2) Connect TP5 (IC503 terminal =PLCK) to the frequency counter’s hot lead, and TP6 to GND.
3) Adjust VR503 to 4450+10 kHz.
(2) Tracking offset adjustment
@ Adjustment toois: Oscilloscope and a normal disc
1) Connect a MA165 diode to either TP13 [pin 2) of IC506 (CPU)] or TP12 [Pin 63) of IC506).
2) Connect TP3 (IC501 20) terminal = TE) to the oscilloscope’s hot lead, and TP2 to GND.
3) Playback a normal disc.
4) Connect TP4 (IC502 (3) terminal =TE) and TP2 (IC501 terminal = VR).
5) Adjust VR501 so the DC level of the tracking error signal (oscilloscope waveform) becomes zero.
Note: Adjust VR501 so that the top and bottom are symmetric while the waveform is at the zero level. The oscilloscope
is to be a DC combination.
___If HLM UTI LA NI Adjust the center of P-P until it
| WV | ii! iI | itl becomes DC level 0.
Fig. 8-5
16 (No. 1755)