4 Adjust the on-time control for five seconds.
5 Adjust the off-time control for five seconds.
(b) Check the following:
1 Check relay K2 for the proper solenoid input signal. Verify there
is no voltage to the base of Q5 during on cycles and about 12vdc during the off cycle.
This voltage can also be checked at the solenoid and collector of Q5.
2 Check relay K1 to ensure the proper turn-on and turn-off signals
are being applied to its coil and the voltage is switched across S5A to the base of Q1.
3 Check for proper control-signal gating on 1C1 and Q4.
4 Check the 5v regulator for proper output, and the overall
appearance of the PCB for shorts, bad solder connections, and/or loose connector
cables when erratic operation occurs.
(2) Symptom: The motor will not turn on, but the solenoid activates
properly. Check IC3 and its associated elements.
(3) Symptom: The on or off cycle does not end. Check for loose or open
connections between timing resistors R11 through 34 to IC2 pins 6 and 7, or IC3 pins 6
and 7. For an on-cycle problem, check resistors R23 through 34 and IC3. For an off-
cycle problem, check resistors R11 through 22 and IC2.
REMOVE AND REPLACE OR REPAIR COMPONENTS
Once you have isolated the causes of equipment malfunctions or defective
components, you must be able to disassemble the apparatus and remove or service the
parts in question. The following paragraphs show you how to accomplish this.
a. Tools Required. You need the tools listed below to remove and replace
components of the Impact programmable suction pump.
A medium-size, slot-head screwdriver.
A medium-size, Phillips-head screwdriver.
A 1/16-inch Allen wrench.
3/8-inch open-end wrench (or a 3/8-inch socket with drive handle).