Pioneer AVIC-X940BT, Service Manual

Page: 143 / 292

AVIC-X940BT/XNUC
143
5 6 7 8
5 6
7
8
C
D
F
A
B
E
1 RF
2 VREF1
Power adjustment
Power adjustment
: Checking terminal for oscilloscope
The figure in parentheses of resistor / capacitor is constant.
VREF1
RF
Universal board
Enlarged
For DVD
t
For CD
t
-
Power Adjustment
Power Adjustment
To turn VR of the circuit for Power adjustment and adjust the optical output level of PU laser diode to make the level
of signal (RF signal) read from the media appropriate level during the reproduction of media, CD and DVD.
It has been decided that Power adjustment circuit (circuit from IMON to CDMP, DVDMP) which adjusts the optical
output level of PU laser diode should be installed on DVD Core Unit in the DVD mecha module.
Therefore, in the replacement of CRG mecha (with PU unit) and DVD Core Unit, Power adjustment should be
implemented.
The Power adjustment method of mecha module is shown below.
Items to be Prepared
Measuring instrument: Oscilloscope (digital or analog)
Frequency band of oscilloscope in DVD whose frequency is higher than CD Adjustable 10 MHz
and higher (enough to check the level)
(In LS2, DVD (x 1.5CLV) MAX RF 6.55 MHz / DVD (x 1.5CLV) MIN RF 1.40 MHz)
DISC: DVD TEST DISC (TDV-582 or TDV-520) Almedio
CD TEST DISC (TCD-782 or TCD-792) Almedio
Adjustment screwdriver : crosshead, No.0, nonmetal (ceramic screwdriver for adjustment)
Line Locating
The following line locating is required.
Connection Diagram