Heathkit IM-4180 - Page 16

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Deviation Meter. It is divided into two sections. The
first section, “General,” contains suggestions of a
general nature in the following areas:
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ea awe ATER Aaalter warht ta
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This part of the Manual will hel
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A. Visual checks and inspections.
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Precautions to observe when bench testing.
C. How to determine the area of the Meter in
which the trouble is located.
The second section consists of a ‘‘Troubleshooting
Chart.” This chart calls out specific problems that
may occur and lists one or more conditions or com-
ponents that could cause each difficulty. The resistor
R-numbers, capacitor C-numbers, diode D-numbers,
and the transistor Q-numbers are identified in these
charts by the same numbers that are used in the ‘‘Parts
Taat aecambly atanae and an tha Srhamatic
List,
in the a@Ssemoiy Sveps, anG Of tne oCneimaus
Diagram. “Circuit Board X-Ray Views”’ (Illustration
Booklet, Page 11) are also provided to help you locate
the components and test points.
NOTE: In an extreme case where you are unable to
resolve a difficulty, refer to the ‘‘Customer Service’
information inside the rear cover of the Manual. Your
Warranty is inside the front cover.
GaeGase Bee eRe SEN Re es
GENERAL
Visual Checks
1. Again make thev ual checks at the end of each
LR
board as
2. About 90 percent of the kits that are returned for
repair do not function properly due to poor con-
+7 m
nections and soldering. Therefore, many trou-
bles can be eliminated by a careful inspection of
connections to make sure they are soldered
properly. Reheat any doubtful connections and
he sure all the wires are soldered at places where
G20 GUseVeuuse Gt psu Visits
several wires are connected.
are installed correctly.
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ho
Page 53
Check the value of each part. Be sure the proper
noart haa haanun
porc 1100 WVUULE V¥L
the Pictorial diagrams as ca alled ‘out in the
wiring instructions. It would be easy, for exam-
pie, to instaii a 22UU0 0 (red-red-red) resistor ina
m) resistor
wi! resistor.
.
aatt eh num in
ty a OLLI VV EE La
a ead in colored
pencil on the Pictorial as it is checked. It is
frequently helpful to have a friend check your
work. Someone who is not familiar with the unit
may notice something yau have consistently
SSULEUY rts aise
overlooked.
Slam
_
Check all component leads connected to the cir-
cuit boards. Make sure the leads do not extend
through the circuit board and make contact with
i parts, suchas shields or
Lili crlions qgitoso i il
the chassis.
Check all the wires and cables that are con-
nected to the circuit boards. Make sure the wires
do noi touch the chassis or other lugs. Make sure
all wires are properly soldered.
You may find it helpful if you read the ‘Circuit -
Description” on Page 57 as you refer to the fold-
in Schematic Diagram.
If the difficulty still is not cured, read the ‘‘Pre-
cautions for Bench Testing” section and the sec-
tion titled ““How to Troubleshoot Your FM De-
viation Meter.”’
Be cautious when you test transistor and IC cir-
cuit ts. Although these devices have a long life
when used properly, they will be almost in-
stantly destroyed when short circuited.
when you make voltage measurements. If the
probe slips, for example, and shorts out a bias or
voltage supply point, it is almost certain to dam-
Wy AL AEWA
Do not remove transistors or IC’s while the De-
viation Meter is turned on, since this would
Do not remove circuit boards while the Devia-
tion Meter is turned on.