JVC xm-px50wt ユーザーズマニュアル

XM-PX50WT

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1. This  design  of  this  product  contains  special  hardware  and  many  circuits  and  components specially  

for  safety  purposes.    For  continued  protection,  no  changes  should  be  made  to  the  original  design  
unless  authorized  in  writing  by  the  manufacturer.    Replacement  parts  must  be  identical  to  those  
used  in  the  original  circuits.    Services  should  be  performed  by  qualified  personnel  only.

2. Alterations  of  the  design  or  circuitry  of  the  product  should  not  be  made.    Any  design  alterations  of  

the  product  should  not  be  made.    Any  design  alterations  or  additions  will    void  the manufacturer`s  
warranty  and  will  further  relieve  the  manufacture  of  responsibility  for  personal  injury  or  property  
damage  resulting  therefrom.

3. Many  electrical  and  mechanical parts  in  the  products  have  special  safety-related  characteristics.    

These  characteristics  are  often  not  evident  from  visual  inspection  nor  can  the  protection  afforded  
by  them  necessarily  be  obtained  by  using  replacement  components  rated  for  higher  voltage,  
wattage,  etc.    Replacement  parts  which  have  these  special  safety  characteristics  are  identified  in  
the  Parts  List  of  Service  Manual.    Electrical  components  having  such  features  are  identified  by  
shading  on  the  schematics  and  by  (    )  on  the  Parts  List  in  the  Service  Manual.    The  use  of  a  
substitute  replacement  which  does  not  have  the  same  safety  characteristics  as  the  recommended  
replacement  parts  shown  in  the  Parts  List  of  Service  Manual  may  create  shock,  fire,  or  other  
hazards.

4. The  leads  in  the  products  are  routed  and  dressed  with  ties,  clamps,  tubings,  barriers  and  the  

like  to  be  separated  from  live  parts,  high  temperature  parts,  moving  parts  and/or  sharp  edges  
for  the  prevention  of  electric  shock  and  fire  hazard.    When  service  is  required,  the  original  lead  
routing  and  dress  should  be  observed,  and  it  should  be  confirmed  that  they  have  been  returned  
to  normal,  after  re-assembling.

5. Leakage  currnet  check  (Electrical  shock  hazard  testing)

After  re-assembling  the  product,  always  perform  an  isolation  check  on  the  exposed  metal  parts  
of  the  product  (antenna  terminals,  knobs,  metal  cabinet,  screw  heads,  headphone  jack,  control  
shafts,  etc.)  to  be  sure  the  product  is  safe  to  operate  without  danger  of  electrical  shock.
Do  not  use  a  line  isolation  transformer  during  this  check.

Plug  the  AC  line  cord  directly  into  the  AC  outlet.    Using  a  "Leakage  Current  Tester",  measure  
the  leakage   current  from  each  exposed  metal  parts  of  the  cabinet , particularly  any  exposed  
metal  part  having  a return  path  to  the  chassis,  to  a  known  good  earth  ground.  Any  leakage  
current  must  not  exceed  0.5mA  AC  (r.m.s.)

Alternate  check  method
Plug   the  AC  line  cord  directly  into  the  AC  outlet.    Use  an  AC  voltmeter  having,  1,000  ohms  
per  volt or  more  sensitivity  in  the  following manner. Connect  a  1,500    10W  resistor  paralleled by 
a 0.15  F AC-type  capacitor  between an  exposed  
metal  part  and  a  known  good  earth  ground.
Measure the  AC  voltage across the resistor  with the 
AC voltmeter. 
Move the  resistor  connection  to eachexposed metal  
part,  particularly  any  exposed  metal part having  a  
return  path  to the  chassis, and meausre the  AC  
voltage  across  the  resistor. Now, reverse the plug in 
the AC outlet and repeat each measurement. voltage 
measured Any must  not exceed 0.75 V  AC  (r.m.s.). 
This  corresponds  to  0.5 mA  AC  (r.m.s.). 

1. This equipment has been  designed  and  manufactured  to  meet  international  safety  standards.
2. It  is  the  legal  responsibility  of  the  repairer  to  ensure  that  these  safety  standards  are  maintained.
3. Repairs  must  be  made  in  accordance  with  the  relevant  safety  standards.
4. It  is  essential  that  safety  critical  components  are  replaced  by  approved  parts.
5. If  mains  voltage  selector  is  provided,  check  setting  for  local  voltage.

Good earth ground

Place this 
probe on 
each exposed
metal part.

AC VOLTMETER
(Having 1000 
ohms/volts,
or more sensitivity)

1500     10W

0.15   F  AC TYPE

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