Chopper Assembly Installation

Section V

paragraphs 5-47to 5-48 Figure 5-6

boards. Use caution when removing them to avoid

damaging mounted components. The Part Number for the assembly is silk screened on the interior of the circuit board to identify it. Refer to Section VI

for parts replacement and Part Number information

5-47. The etched circuit boards are a plated-through type. The electrical connection between sides of the board is made by a layer of metal plated through the component holes. When working on these boards, observe the following general rules.

a.Use a low-heat (25 to 50 watts) small-tip soldering iron, and a small diameter rosin core aoider.

b. Circuit components can be removed by placing the soldering iron on the component lead on either aide of the board, and pulling up on lead. If a component is obviously damaged, clip leads as close to component as possible and then remove. Excess heat can cause the

circuit	and board to separate, or cause damage
to the	component.

F i g u r e 5 - 6 . A 4

TM 11-6625-1614-15

Model 410C

c. Component	lead	hole should be	cleaned
before inserting	new	lead.

d. To replace components, shape new leads and insert them in holes. Reheat with iron and add solder as required to insure a good electrical connection.

e. Clean excess flux from the connection and adjoining area.

f. To avoid surface contamination of the printed circuit, clean with weak solution of warm water and mild detergent after repair. Rinse thoroughly

with clean water. When completely dry, spray lightly with Krylon (#1302 or equivalent).

5-48. CHOPPER ASSEMBLY INSTALLATION.

a . Figure 5 - 6 describes the physical orien - tation of chopper assembly on printed circuit board. Note location of chopper assembly serial number in relation to circuit board pins.