COMPONENT MAINTENANCE MANUAL
IN 1502H RADAR INDICATOR
TM109102
5-9
May/01
NOTE:
Do not bend or crimp component leads to hold component in position
prior to soldering. It is recommended that component leads remain
straight when protruding through board. Keeping the leads straight
makes component replacement easier and prevents damage to the
circuit board when removing components.
(6) Using solvent and pipe cleaner tips, carefully scrub both sides of the circuit board
(holes, pads, etc.) from which component was removed.
(7) Bend leads of new component so that component fits freely into holes in circuit board.
(8) If component has polarity markings (electrolytics, diodes), ensure that component is
oriented the same as the removed component. Insert new component through holes
in circuit board. Ensure that component is flush with circuit board or is in the same
position as was the removed component.
(9) Use flux and solder sparingly and solder the component to circuit board from the track
side of the board. Do not use excessive heat. Ensure that position of component does
not change during soldering.
(10)Carefully inspect solder joints to ensure that excess solder has not been used and
that no short circuits are in evidence. Solder should fill the circuit board hole through
which the component lead is inserted.
(11)Using small diagonal cutters or end nippers, snip excess leads from components.
(12)If more than one component is being replaced, repeat the above paragraphs for each
component.
(13)When all components have been replaced, use a small brush or pipe cleaner and
solvent to clean new solder joints. Ensure that all flux and solder rosin is removed.
Use a round toothpick to help remove heavy deposits of rosin. Solder joints should be
smooth, bright and clean when properly soldered and cleaned.
E. Replacing Semiconductors on Printed Circuit Boards
Never remove or install a semiconductor device with the supply voltage turned on.
Plugging in or removing a transistor can produce voltage transients that might damage
the device.
When removing or installing soldered-in diodes, always apply a heat sink between
semiconductor body and solder terminal or standoff. The heat sink will dissipate heat from
soldering iron and prevent diode from being damaged. Always use a low wattage
soldering iron and apply heat only long enough to make a good solder joint.
CAUTION:
DO NOT REMOVE HEAT SINK UNTIL SOLDER JOINT HAS COOLED.
(1) Note tab location, lead spacing or lead numbers before proceeding.
The document reference is online, please check the correspondence between the online documentation and the printed version.
