TM 5-3810-295-34
8-3.
Cleaning, Inspection and Repair
are securely attached.
a. Cleaning is limited to the removal of corrosion from
terminals and lugs and removing dirt from external
8-5.
Testing
component cases. Clean program cards with an
a. LSTC Test Procedure.
Before making
approved cleaning solvent and buff terminal with a
detailed tests tabulated below on the Load Moment Safety
pencil eraser.
Computer, make operator's test consisting of physical
b. Inspect the wiring for loose connections, corroded
inspection and operation check. This is recommended to
terminals and damaged components.
eliminate the problems which are most likely to occur. A
c. Repair is limited to replacement of major assemblies
complete system checkout is listed in table 8-1 and is to
of the load moment safety computer as described in
be followed in sequence. If a specific criteria is not met,
paragraph 8-5a.
refer to corrective action as detailed in paragraph 8-5b.
8-4.
Reassembly and Installation
CAUTION
Use great care in making voltage readings to
NOTE
prevent damage to LSTC components by
shorting or grounding of test leads or contacts.
Angle transducer axis must be parallel to
boom axis on installation.
a. Install and connect wiring as shown in figure 8-1.
b. Check to be sure all connections are correct and
Table 8-1. Test Procedure
Procedure
Corrective
Step
Test
action
1
1
Power-In
Remove all cables from end of LSTC Console With Master switch turned "ON". Measure with
voltmeter input voltage on P4 cable (79R375); pins "A" to "H". Proper voltage will be between
24.OVDC to 32.0VDC.
2
Bell
Measure with ohmmeter from P4- F to P4-G on cable to assure
2
Approximate ohm load of bell should be 36 ohms (+3 ohms).
-
3
"Floats/tires" switch
3
position and closed in "Tires".
4
LSTC fuse
Connect Cable P4 to LSTC Console. Turn LSTC Control Switch to" RUN". Two fuses on front
4
panel are good if knobs are not lighted. This then puts power into the computer for further checks.
5
LSTC power
Measure with a D.C. Voltmeter from pin P2 -G to P2 -J on LSTC Console. Pin "J" is positive.
5
Voltage will be (battery voltage minus approx. 1.7V) 22.3 to 30.3 VDC. Record.
6
Regulated supply
Measure with D.C. Voltmeter from Pin P6-A to P6-B on LSTC "A" Console will be positive.
5
Voltage should be approximately between 19.1V & 18.3V.
7
Pos. 9V bus
Measure with D.C. Voltmeter from Pin P6-A to P6-B on LSTC "A" Console will be positive.
5
Voltage should be V2 of voltage step 6 or between +9.550VDC & +9.150VDC. Record value
.
8
Neg. 9V bus
Measure with D.C. Voltmeter from Pin P6-B to P6-C on LSTC Console. "B" will be negative
5
Voltage should be V2 of voltage in step 6 or between -9.550VDC or -9.150 VDC. Record value
.
9
Balanced Buses
Subtract & compare. Recorded values of Steps 7 & 8 must be within .040VDC of each other
5
.
10
Load cell power
Measure with A.C. Voltmeter from Pin P3-A to P3-B. No load voltage will be 7.250 t .02VAC.
5
oscillator voltage
.
11
Measure frequency using scope to verify the frequency to be between 2400hz and 2570 hz. (416.6
5
micro-see. to 389.1 micro-sec.)
12
Shield connection
Load Cell Cable Shield is terminated at LSTC Console. Verify connection
5
using ohmmeter to check continuity from Pin P3-E to LSTC Console cabinet.
(Using ohmmeter also check for continuity from LSTC Console to machine
frame. Ground Console if necessary.)
13
Boom angle power
Measure using D.C. Voltmeter from Pin P1-A to P1-B on LSTC Console. No
5
load voltage will be 6.4VDC t .1VDC. Pin "B" will be positive.
14
"Floats" light power
Place "Floats/Tires" Switch in "Floats" Position. Measure using D.C
5.
Voltmeter from Pin P2-F to P2-G. Pin " F" will be positive. Compare Voltage
.
to voltage recorded in Step 5; should be within 0.5V
15
"Tires" light power
Place " Floats/Tires" Switch in "Tires" Position. Measure using D.C. Voltmeter
5
from Pin P2-E to P2-6. Pin "E" will be positive.
16
Remote indicator
Test Cable P2-P5 (79T170) per Cable Test Instructions.
6
cable
17
Remote indicator
Measure resistance using an ohmmeter at connector P5 on Remote Indicator as
7
follows: P5-A to P5-B approx. 445-455 ohms.
Change 1 8-5
