Section II. TOOLS AND TEST EQUIPMENT

TM 11-6625-444-14-2

Section II. TOOLS AND TEST EQUIPMENT

required for maintenance of the voltmeter (see

6-4. Tools and Test Equipment Required

table 6-1). No special tools are required.

This section contains a listing of test equipment

Reference

Nomenclature

Common Name

NSN

Paragraph

Dc voltage calibrator

John Fluke Model 332B

6625-00-150-6994

6-14

Ac voltage calibrator

John Fluke Model

6625-01-063-6325

6-14

5200A/5215A

H.P. Model 180D

Oscilloscope

6625-00-022-8228

5-21

Gen. Rad. W10MT3AS3

Variable transformer

6120-00-168-3705

AN/USM-451

Multimeter

6625-01-060-6804

6-7

CP-772 A/U

Frequency counter

6625-00-973-4837

Section III. TROUBLESHOOTING

(b) Dc Volts Attenuator/Buffer (A1)

6-5. General

(c) A/D Converter (A1)

Troubleshooting information supplied in this

(d) Up/Down Detector (A1)

section is in the form of flow charts that will fa-

cilitate locating a defective assembly or com-

(e) Function Select Logic (A2)

ponent rapidly.

(f) Range Select Logic (A2)

(g) Digital Counter/Display Drivers (A2)

First check for loose plug-in assemblies, im-

p r o p e r l y mated connectors, (figures 6-2 and

(h) Autorange Circuits (A2)

6-3) broken wires, physically damaged (burned

(i) Clock Circuits (A2)

or broken) components and other obvious prob-

lems. Next, the characteristics detailed in the

( j ) Display (A3)

Performance Assurance Checks of Section V

(k) True Rms Converter (A7)

( b e g i n n i n g with paragraph 6-13) should be

checked and any discrepancies noted. This will

(l) D C Ratio Amplifier (A9)

serve as an aid to pin-pointing the source of

trouble.

With the aid of the flow charts, figure 6-4 to

6-7, it should be possible to isolate the fault to

6-6. Fault Isolation

one of these sections. Once the problem has

been reduced to a major section, refer to the

applicable schematic(s), figures FO-2 through

The voltmeter consists of the following major

sections (also see Maintenance Allocation Chart:

FO-14, at the back of this manual to further

isolate to the component level. Also refer to the

logic tables in Chapter 5, Section II.

(a) Power Supply (A1, A2)

6-4