VTM Confidence Tests.

(3) The display on the VTM should show .8.8.8.8 for about two

seconds and then change to four dashes (- - - -). If this sequence

is NOT displayed, the STE test set is faulty, and the following

actions should be taken:

(a) If nothing appears on the display, check all cable

connectors for tightness; then, if nothing appears on the display,

troubleshoot the STE test set for the symptom NO VTM DISPLAY ON POWER

UP, in accordance with TM 9-4910-751-14-1, chapter 5.

(b) If any one dot, number eight, or dash does not appear on

the display, replace the faulty display module, in accordance with TM

9-4910-751-14-1, chapter 5.

(c) If the VTM display shows blank, then shows .8.8.8.8, then

is blank again, troubleshoot the STE test set for the symptom VTM

DISPLAYS BLANK, THEN .8.8.8.8, THEN BLANK, as outlined in TM 9-4910-

751-14-1, chapter 5.

b. VTM Confidence Tests.

Two VTM confidence tests must be

performed as the first steps in the self-test (refer to figure 46 on

page 63).

(1) VTM Confidence Test 66.

To perform the first VTM confidence

test, follow these steps:

(a) Set the TEST SELECT switches on the VTM to 66.

(b) Press the TEST button on the VTM.

(c) The display on the VTM should show 0066. If it does not

show 0066, troubleshoot the test set for the symptom VTM DOES NOT

DISPLAY 0066, in accordance with the instructions contained in TM

9-4910-751-14-1, chapter 5.

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