Samsung YP-U1, Service Manual

Samsung Electronics

1-2

1-1 Safety Precautions (Continued)

7. Components, parts and wiring that appear 

to have overheated or that are otherwise 
damaged should be replaced with parts 
that meet the original specifications.  

Always determine the cause of damage or

overheating, and correct any potential 
hazards

8. Observe the original lead dress, especially 

near the following areas:  Antenna 
wiring, sharp edges, and especially the

AC and high voltage power supplies.  
Always inspect for  pinched, out-of-place, 

or frayed wiring.   Do not change the 
spacing between components and the 
printed circuit board.  Check the AC 
power cord for damage.  Make sure that 
no wires or components touch thermally 
hot parts.

9. Product  Safety Notice: 

Some electrical and mechanical parts 

have special safety-related characteristics 

which might not be obvious from visual        
inspection. These safety features and the 
protection they give might be lost if the 
replacement component differs from the 
original--even if the replacement is rated 
for higher voltage, wattage, etc.  

10 Components that are critical for safety are 

indicated in the circuit diagram by 

shading,         or          .  Use replacement 
components that have the same ratings, 
especially for flame resistance and 
dielectric strength specifications. A
replacement part that does not have the 
same safety characteristics as the original 
might create shock, fire or other hazards.

1-2 Servicing Precautions

1. Servicing precautions are printed on the 

cabinet. Follow them.

2. Always unplug the unit's AC power cord from

the AC power  source before 
attempting to: (a)  Remove or reinstall any
component or assembly, (b) Disconnect an
electrical plug or  connector, (c) Connect a
test component in parallel with an 
electrolytic capacitor.

3. Some components are raised above the 

printed circuit board for safety. An 
insulation tube or tape is sometimes used.
The internal wiring may be clamped to 
prevent contact with thermally hot 
components. Reinstall all such elements to
their original position.

4. After servicing, always check that the 

screws, components and wiring have been
correctly reinstalled. Make sure that the 
portion around the serviced part has not
been damaged.

5. Check the insulation between the blades of

the AC plug and accessible conductive parts
(examples:  metal panels, input terminals
and earphone jacks).

6. Insulation Checking Procedure: Disconnect

the power cord from the AC source and 
turn the power switch ON.  Connect an 
insulation resistance meter (500V) to the
blades of the AC plug. 

The insulation resistance between each 
blade of the AC plug and accessible 
conductive parts (see above) should be
greater than 1 megohm.

7. Never defeat any of the B+ voltage 

interlocks.  Do not apply AC power to the
unit (or any of its assemblies) unless all
solid-state heat sinks are correctly installed.

8. Always connect a test instrument's ground

lead to  the instrument  chassis ground 
before connecting the positive lead;  always
remove the instrument's  ground lead last.

Precautions

Warning1: First read the "Safety Precautions" section of this manual. If some unforeseen circumstance

creates a conflict between the servicing and safety precautions, always follow the safety  precautions.