CHAPTER 7 DIRECT SUPPORT (INTERMEDIATE) MAINTENANCE INSTRUCTIONS

CHAPTER 7

DIRECT SUPPORT (INTERMEDIATE) MAINTENANCE INSTRUCTIONS

Section I. GENERAL

7-1. Scope

This chapter provides specific instructions for all maintenance functions authorized direct support maintenance personnel

by the maintenance allocation chart (Appendix B). Included are maintenance, troubleshooting and repair instructions.

7-2. Purpose

These maintenance instructions are for use following isolation of a J-SIIDS malfunction to the Capacitance Proximity

Sensor (CPS).

7-3. Periodic Checks and Services

There are no scheduled preventive maintenance procedures required for the CPS.

Section II. TOOLS AND EQUIPMENT

7-4. Standard Tools and Equipment

The CPS can be maintained with standard tools and a voltohmmeter.

7-5. Special Tools and Equipment

No special tools and equipment are required for direct support maintenance of the CPS.

Section III. TROUBLESHOOTING

7-6. Visual Inspection

Before troubleshooting the CPS make a thorough visual inspection. Check sensor cable and PCS for damage and

evidence of failure. Check CPS housing interior for presence of moisture of foreign matter.

7-7. Troubleshooting

If the CPS malfunctions refer to Table 7-1. Find the trouble that most closely corresponds to that encountered, note the

probable cause (s) and perform the corrective action (s) indicated. If the corrective action in Table 7-1 does not correct

the malfunction the trouble is in the circuit board assembly. Figure FO-1, (located in back of manual) PCS schematic

diagram and the preliminary checks given in Chapter 2 will help to identify the trouble.

CAUTION

Do not adjust R29 Sensitivity Adjust. This is a factory adjustment and calibration

procedures are not included in this manual.

Table 7-1. Installed System Troubleshooting

Trouble

Probable cause

Corrective action

Continuous

proximity

and

tamper

No power reaching CPS.

Troubleshoot 20 VDC power line to

alarms.

CPS.

Continuous proximity alarm, tamper

Proximity alarm wiring open.

Troubleshoot alarm wiring.

alarm normal

Continuous tamper alarm, proximity

Tamper alarm wiring open.

Troubleshoot alarm wiring.

alarm normal.

470K line termination resistor not

Check 470K line termination resistor;

installed or open.

install or replace.

Continuous

tamper

alarm,

Sensor cable shorted.

Troubleshoot sensor cable

proximity alarm.

Intermittent proximity false alarms.

Poor sensor cable connection to one

Inspect sensor cable equipment

or more item of equipment.

connections; repair as necessary.

Foreign objects touching or near

Inspect around, behind, and under

protected equipment

protected equipment, remove dirt,

paper, wastebaskets, or any other

objects which might disturb the static

capacitance.

7-1