PT3-H AVC3-U
NOTE: These components are affixed with glue. Be careful not to break or damage any foil under the
component or at the pins of the ICs when removing. Usually applying heat to the component for a short
time while twisting with tweezers will break the component loose.
Leadless Chip ComponentsHow to Replace Flat-lC
(surface mount)?Required Tools?
Chip components must be replaced with identical? Soldering iron ? iron wire or small awl
chips due to critical foil track spacing. There are no? De-solder braids ? Magnifier
holes in the board to mount standard transistors or1. Remove the solder from all of the pins of a Flat-lC
diodes. Some chip capacitor or resistor board solderby using a de-solder braid.
pads may have holes through the board, however the
hole diameter limits standard resistor replacement toDe-Solder
1/8 watt. Standard capacitors may also be limited forBraid
the same reason. It is recommended that identical
chip components be used. .Soldering
Iron
Chip resistors have a three digit numerical resistance
code -1st and 2nd significant digits and a multiplier.2. Put the iron wire under the pins of the Flat-lC and
Example: 162 = 1600 or 1.6K& resistor, 0 = 0&pull it in the direction indicated while heating the
pins using a soldering iron. A small awl can be
(jumper).
used instead of the iron wire.
Chip capacitors generally do not have the value
Iron
indicated on the capacitor. The color of the componentWire
indicates the general range of the capacitance.Awl
Chip transistors are identified by a two letter code. The
first letter indicates the type and the second letter, the
grade of transistor.Soldering
Chip diodes have a two letter identification code asSolderingPullIron
Iron
per the code chart and are a dual diode pack with
either3. Remove the solder from all of the pads of the
common anode or common cathode. Check the partsFiat-lC by using
list for correct diode number.a de-solder braid.Soldering
Iron
Component Removal
1. Use solder wick to remove solder from componentDe-Solder
end caps or terminals.Braid
2. Without pulling up, carefully twist the component
with tweezers to break the adhesive.Flat-IC
3. Do not reuse removed leadless or chip
components since they are subject to stress4. Position the new Flat-lC in place (apply the pins of
fracture during removal .the Flat-lC to the soldering pads where the pins
Chip Component Installationneed to be soldered). ProperlyPolarity Symbol
determine the positions of the
1. Put a small amount of solder on the board
soldering pads and pins by
soldering pads.
correctly aligning the polarity
2. Hold the chip component against the solderingsymbol.
pads with tweezers or with a miniature alligator
clip and apply heat to the pad area with a 30 watt
iron until solder flows. Do not apply heat for more5. Solder all pins to the soldering pads using a fine
than 3 seconds tipped soldering iron.
Chip Components
TYPE
CGRADESOLDER
CAPS
BSolderSoldering
TRANSISTORCAPACITORIron
E
1ST DIGIT
6. Check with a magnifier for solder bridge between
2ND DIGIT
COMMON CATHODEthe pins or for dry joint between pins and soldering
MULTIPLIERpads. To remove a solder bridge, use a de-solder
= 1600 = 1.6Kbraid as shown in the figure below.
De-Solder
ANODESSOLDER CAPSBraid
MH DIODERESISTOR
BridgeSoldering
SolderIron
7 |
ACEC
