COMPONENT MAINTENANCE MANUAL
IN 1502H RADAR INDICATOR
TM109102
5-8
May/01
NOTE:
Always add a small amount of rosin flux or rosin-core solder while
resoldering connections.
(4) Reference to the “component side” of a printed circuit board in this manual means the
side on which the components are located. “Track side” refers to the other side.
D. Replacing Resistors, Capacitors and Diodes
(1) Before removing diodes or polarized capacitors (electrolytics), note polarity markings
and orientation on the circuit board.
(2) Using a small diagonal cutter, carefully cut off both component leads, leaving about
1/6 of an inch of lead protruding from the circuit board. Remove the component.
NOTE:
If it is desired to disconnect only one lead for component substitution (such
as may be required during troubleshooting), refer to paragraph 4.D.(5)
below.
WARNING: DO NOT APPLY HEAT AT A PLATED-THRU HOLE FOR MORE THAN 8
SECONDS. USE A 20 TO 50 WATT SOLDERING IRON ONLY.
(3) Grasp a cut-off lead (on component side of board) with a small pair of needlenose
pliers. Apply soldering iron (with a little flux on the tip) to circuit board where lead
passes through circuit board. Track side can also be used. If track side is used for
unsoldering, ensure that the correct lead and circuit board point is located. As soon as
solder melts, carefully remove cut-off lead from component side. If excessive force is
applied, the plated-through hole may be pulled out of the board with the lead.
(4) Using soldering iron, reheat point on circuit board from which a lead has been
removed. When remaining solder melts, apply and actuate solder sipper to remove
solder. Repeat for remaining lead. Use solder sipper as required until holes in board
are clean (as indicated by no solder on the walls, top or bottom of the holes in the
circuit board).
(5) If only one lead is being disconnected, for component substitution during
troubleshooting, proceed as follows:
(a) From component side, grasp lead close to circuit board with a small pair of
needlenose pliers.
(b) From track side of circuit board, heat point on circuit board where lead passes
through board. When solder melts, carefully lift lead upward until lead has cleared
circuit board.
(c) Repeat paragraph 4.D.(4) and ensure that all solder is removed from hole.
(d) Replace lead by inserting lead through hole in circuit board and resoldering to
board. Use flux and solder sparingly.
The document reference is online, please check the correspondence between the online documentation and the printed version.
