JVC SP-WA25, Service Manual

Page: 20 / 71

1-20 (No.MB141)
5.2.3 PickUp Head Initial Position
PickUp Head Initial Position
(1) 1. Move Pick Up Head to inner direction until pin5 of MJ4="L"
(2) 2. If pin5 of MJ4="L", then move Pick Up Head to outer direction for a short time.
(3) 3. Turn On the Laser of Pick Up Head to judge that disc is present or not.
Does Pick Up
Move to inner
direction?
Does Pick Up
Move to out
direction again?
Does Laser Turn
On?
Check voltage at
pin8 of RCN1 is
about 2.5V?
Check BUS line between RIC1 and
SIC1,SIC1 and MIC1
Is pulse of 2.5
+-2.5V developed
at pin3,4 of MJ4?
Is pulse of 2.5
+-2.5V developed
at pin13 of SIC1
Is pin5 of MJ4 =
"L" appeared?
Replace Pick Up Head
Check line between SIC1
and MJ4
Check
connection
between PCB
and MECHA
Check
connection
between PCB
and MECHA
Check
peripheral
circuit of SIC1
and DRIC1
Check BUS
line between
SIC1 and MIC1
N
N
N
N
N
N
N
Y
Y
Y
Y
Y
Y
3
OK