Chapter 1. General Description; Important Service Safety Precaution; Important Service Notes (For U.s.a Only) - Sharp DK-A1 Service Manual

CHAPTER 1. GENERAL DESCRIPTION

[1]

Important Service Safety Precaution

CAUTION : "These servicing instructions are for use by qualified service personnel only. To reduce
the risk of electric shock do not perform any servicing other than that contained in the operating
instructions unless you are qualified to do so".
WARNING
1. For continued safety, no modification of any circuit should be
attempted.
2. Disconnect AC power before servicing.
3. CAUTION: "Danger of explosion if battery is incorrectly replaced. Replace only with the same
or equivalent type".
[2] Important Service Notes (for
BEFORE RETURNING THE AUDIO PRODUCT
(Fire & Shock Hazard)
Before returning the audio product to the user, perform
the following safety checks.
1. Inspect all lead dress to make certain that leads are not
pinched or that hardware is not lodged between the
chassis and other metal parts in the audio product.
2. Inspect all protective devices such as insulating
materials, cabinet, terminal board, adjustment and
compartment covers or shields, mechanical insulators
etc.
3. To be sure that no shock hazard exists, check for
leakage current in the following manner.
* Plug the AC line cord directly into a 120 volt AC outlet.
* Using two clip leads, connect a 1.5k ohm, 10 watt
resistor paralleled by a 0.15µF capacitor in series
with all exposed metal cabinet parts and a known
earth ground, such as conduit or electrical ground
connected to earth ground.
* Use a VTVM or VOM with 1000 ohm per volt, or
higher, sensitivity to measure the AC voltage drop
across the resistor (See diagram).
* Connect the resistor connection to all exposed metal
parts having a return path to the chassis (antenna,
metal cabinet, screw heads, knobs and control shafts,
escutcheon, etc.) and measure the AC voltage drop
across the resistor.
CAUTION: FOR CONTINUED
PROTECTION AGAINST FIRE
HAZARD, REPLACE ONLY WITH
SAME TYPE F800, 630mA, 125V/
F801 5A, 125V FUSES.
ATTENTION: POUR ASSURER
UNE LONGUE PROTECTION CONTRE
UN INCENDIE, REMPLACER SEULEMENT
PAR UN FUSIBLE DE
TYPE F800 , 630mA, 125V/
F801 5A, 125V FUSES.
U.S.A only)
1 – 3
1 – 1
VTVM
AC SCALE
1.5k ohms
10W
0.15 µ F
TEST PROBE
TO EXPOSED
METAL PARTS
All check must be repeated with the AC line cord plug
connection reversed.
Any reading of 0.3 volt RMS (this corresponds to 0.2
milliamp. AC.) Or more is excessive and indicates a
potential shock hazard which must be corrected before
returning the audio product to the owner.
DK-A1/DK-A1BK
CONNECT TO
KNOWN EARTH
GROUND