Page 1
SECTION 1
GENERAL
This section is extracted from
instruction manual.
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1. Check the area of your repair for unsoldered or poorly-soldered
connections. Check the entire board surface for solder splashes
and bridges.
2. Check the interboard wiring to ensure that no wires are
"pinched" or contact high-wattage resistors.
3. Look for unauthorized replacement parts, particularly
transistors, that were installed during a previous repair. Point
them out to the customer and recommend their replacement.4. Look for parts which, through functioning, show obvious signs
of deterioration. Point them out to the customer and
recommend their replacement.
5. Check the B+ voltage to see it is at the values specified.
6. Flexible Circuit Board Repairing
-Keep the temperature of the soldering iron around 270ËšC
during repairing.
-Do not touch the soldering iron on the same conductor of the
circuit board (within 3 times).
-Be careful not to apply force on the conductor when soldering
or unsoldering.
SAFETY CHECK-OUT
After correcting the original service problem, perform the following
safety checks before releasing the set to the customer.
1POWER switch
2Battery check indicator
When you turn the power on, the battery check indicator lights up
momentarily. This is normal. The light tells you that the battery still
has life. When the battery becomes weak, the indicator lights dimly
or does not light at all.
3L-shaped stereo miniplug (gold plated)
4Battery box
You can clip the battery box to your tie, lapel or pocket.
5Microphone jack
6L-shaped stereo miniplug (gold plated)
7Battery compartment
8Microphone
9Holder clip
AInterlock the projection of the holder to the groove on the
microphone.
BThis microphone holder allows you to tilt the microphone 45°
backward or forward.
Page 2
SECTION 2
DIAGRAMS
2-1. SCHEMATIC DIAGRAM
TOTAL CURRENT
MIC UNIT
CONNECT : 700uA
DISCONNECT : 460uA
LITHIUM BATTERY
(L CH)
(R CH)
2
R22 3.9KR21 2.2M R23
3K
C22
0.01
FQ2
2SC4116YG
MIC AMP
R24
3K
C241
F
R12
2.2M R13
3K
C12
0.01
FC14
2.3
0.5 1.0
2.3
0.5 1.01
F
3.9KR11
Q1
2SC4116YG
MIC AMP
L
R
R14
3K
2.9
MIC UNIT
Note on Schematic Diagram:
-All capacitors are in µF unless otherwise noted. pF: µµF
50 WV or less are not indicated except for electrolytics
and tantalums.
-All resistors are in -„¦ and
1/4
W or less unless otherwise
specified.
-% : indicates tolerance.
-C: panel designation.
-U: B+ Line.
-Power voltage is dc 3 V and fed with regulated dc power
supply from battery terminal.-Voltages and waveforms are dc with respect to ground
under no-signal (detuned) conditions.
-Voltages are taken with a VOM (Input impedance 10 M-„¦).
Voltage variations may be noted due to normal produc-
tion tolerances.
-Signal path.
F: MIC
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