SG-2000 MANUAL
175
The SGC Building, 13737 S.E. 26th St. Bellevue, WA. 98005 USA
©1995, SGC, Inc.
TEL: (206) 746-6310 FAX: (206) 746-6384
Q20 and D1 energizing the relay, K14. If a voltage in excess of the zener
breakdown voltage of D11 is applied, transistors Q19 and Q21 turn on and Q20
turns off. Diode D13 provides protection from transient voltage spikes.
23.2.3
Test Setup
Ensure screws holding the final transistors; Q6, Q7, Q10 and Q11 have 12 inch
lbs. of torque.
Using the LPA sample board, visually check:
Check all electrolytic capacitors for polarity.
Check for any solder bridges.
Ensure R21 is not touching the PCB.
Install any missing parts, except IC3, IC4, F1, F2 and F3.
Check the orientation of transistors and other parts.
Check the wires on T10 and T8. The colors should alternate green and red.
Check the wires on T6. They should crisscross as shown in the figure below.
Notice, the order of the wires on the teroid does not have to be the same order
as the solder connections.
red
orange
yellow
green
green
yellow
orange
red
Side View
red
yellow
orange
green
green
orange
yellow
red
Top View
Set the resistors,
R20
to approximately mid value
R28
to approximately mid value
R2
to approximately mid value
R32
to approximately mid value
R41
to fully clockwise
R42
to fully clockwise