Honeywell bendis king KLN 94 Maintenance Manual page 69

BENDIX/KING
F. PC Board, Multi-Lead Component Removal (IC's, etc.)
G. Replacement of Power Transistors
H. Replacement of Printed Circuit Board Protective Coating
Page 5-30
4. Insert replacement component observing correct orienta-
tion.
1. Remove component by clipping each lead along both sides.
Clip off leads as close to component as possible. Discard
component.
2. Heat hole from solder side and remove clipped lead from
each hole.
3. Melt solder in each hole, and using a desoldering tool, re-
move solder from each hole.
4. Insert replacement component observing correct orienta-
tion.
5. Solder component in place from farside of board. Avoid sol-
der runs. No solder is required on contacts where no traces
exist.
1. Unsolder leads and remove attaching hardware. Remove
transistor and hard-coat insulator.
2. Apply Thermal Joint Compound Type 120 (Wakefield Engi-
neering, Inc.) to the mounting surface of the replacement
transistor.
3. Reinstall the transistor insulator and the power transistor us-
ing hardware removed in step (1).
4. After installing the replacement transistor, but before making
any electrical connections, measure the resistance between
the case of the transistor and the chassis, to ensure that the
insulation is effective. The resistance measured should be
greater than 10MΩ.
5. Reconnect leads to transistor and solder in place.
WARNING
CONFORMAL COATING CONTAINS TOXIC
VAPORS! USE ONLY WITH ADEQUATE VEN-
TILATION.
1. Clean repaired area of printed circuit board per instructions
in the Cleaning section of this manual.
2. Apply Conformal Coating, Humiseal #1B-31 HYSOL PC20-
35M-01 (Humiseal Division, Columbia Chase Corp., 24-60
Brooklyn Queens Expressway West, Woodside, N.Y.,
11377) P/N 016-01040-0000.
3. Shake container well before using.
15599M00.JA
KLN 94
Rev 0, Sept/2000