Heathkit AA-1214 User Manual

L..
I.....J
L,
L
L..
I...;
L
L
L
~ HEATHKIT ~
=NMfflHU-14
45
VISUAL CHECKS
1. About 90% of the kits that are
returned for repair do not function
properly due to poor connections
and soldering. Therefore, many
difficulties can be eliminated by a
careful inspection of connections
to make sure they are soldered as
described in the "Soldering" section
of the "Kit Builders Guide." Reheat
any doubtful connections and be sure
all the wires are soldered at places
where several wires are connected.
2. Check each circuit board to be sure
there a r~ no so 1 der bridges betwee.n
adjacent connections. Remove any
solder bridges by holding a clean
soldering iron tip between the two
points that are bridged until the
excess solder flows Q.Qkill the tip
of the soldering iron.
3. Be sure each transistor and the
integrated circuit is in the proper
location (correct part number and
type number). Be sure that each
transistor lead is positioned
properly and has a good solder
connection to the foil. Check the
integrated circuit for proper
positioning and good contact at all
pin connections.
4. Check capacitor values carefully.
Be sure the proper part is wired
into the circuit at each capacitor
location. For example, it would be
easy to mistake a .001 µF capacitor
for a 100 pF capacitor. Always
check the polarity of electrolytic
capacitors to be sure they are
installed correctly.
5. Check each resistor carefully. It
would be easy, for example, to install
a 1200 n (brown-red-red) resistor
where a 220n (red-red-brown) resistor
is called for. A resistor that is
discoloured, or cracked, or shows
any sign of bulging would indicate
that it is faulty and should be
replaced.
6. Be sure the correct diode is installed
at each diode location, and that the
banded end is positioned correctly.
7. Recheck the wiring. Trace each lead
in coloured penci l 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
you have consistently overlooked.
8. Check all component leads connected
to the circuit boards. Make sure the
leads do not extend through the
circuit board and make contact with
other connections or parts.

Heathkit AA-1214 Specifications

General

Brand	Heathkit
Model	AA-1214
Category	Amplifier
Language	English