Table 5-2. Control-interface Unit Troubleshooting - Continued

TM 11-6625-2937-13

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

SHORT INDICATOR DS3 DOES NOT LIGHT WITH DIGITAL TESTER UUT POWER OFF AND CONTROL

INTERFACE

UNIT

MODE

SELECT IN EITHER MODULE TEST ENC OR MODULE TEST DEC.

Step 1. Check indicator lamp by replacement (para 3-14a).

Replace defective indicator lamp.

Step 2. Check power fault detection circuits on circuit card assembly Al (malfunction 4, step 2).

TEST ON INDICATOR LAMP DOES NOT LIGHT DURING BITE TEST.

Step 1. Check indicator lamp by replacement (para 3-14a).

Replace defective indicator lamp.

Step 2. Check derived timing No. I circuit card assembly A4 (table 5-1, steps 10 through 13).

Replace circuit card assembly A4 (para 5-15).

TEST ON INDICATOR LAMP LIGHTS, DURING BITE TEST, BUT MODEIPOWER I NDICATOR LAMPS DO

NOT LIGHT.

Step 1. Check indicator lamps by replacement (para 3-14a).

Replace defective indicator lamps.

Step 2

Check STE microprocessor circuit card assembly A2 (para 5-29fi.

Replace circuit card assembly A2 (para 5-15).

Step 3. Check STE RAM/ROM circuit card assembly A3 (para 5-29g).

Replace circuit card assembly A3 (para 5-15).

Step 4. Check derived timing No. 2 circuit card assembly AS (para 5-29t).

Replace circuit card assembly AS (para 5-15).

Step 5. Check circuit card assembles Al, A6 and A7 0arM 5-29e,Jand k).

Replace defective circuit card assemblies (para 5-15).

MODE/POWER INDICATOR LAMPS LIGHT AND REMAIN ON DURING BITE TEST.

Step 1. Check PIT and test ROM circuit card assembly A6 (para 5-29j).

Replace circuit card assembly A6 (para 5-15).

Step 2. Check circuit card assemblies Al, A2, A3 and A7 (para 5-29e, f g and k).

Replace defective circuit card assemblies (para 5-15).

TEST NUMBER DISPLAY INDICATES 00.0 AT END OF TEST CYCLE.

Step 1. Check STE microprocessor circuit card assembly A2 (para 5-29fi.

Replace circuit card assembly A2 (para 5-15).

Step 2. Check STE RAM/ROM circuit card assembly A3 (bra 5-29g).

Replace circuit card assembly A3 (para 5-15).

Step 3. Check derived timing No. 2 circuit card assembly AS (para 5-290.

Replace circuit card assembly AS (para 5-15).

Step 4. Check circuit card assemblies Al, A6 and A7 (para 5-29e, J and k).

TEST NUMBER DISPLAY INDICATES 00.1 OR 00.2 AT END OF TEST CYCLE.

Step 1. Check STE RAM/ROM circuit card assembly A3 (para 5-29g).

Replace circuit card assembly A3 (para 5-15).

Step 2. Check circuit card assemblies Al, A2, A6 and A7 (par 5-29e, f J and k).

Replace defective circuit card assemblies (para 5-15).

11.

TEST NUMBER DISPLAY INDICATES 00.3 OR 00.4 AT END OF TEST CYCLE.

Step 1. Check PIT and test ROM circuit card assembly A6 (m 5-29).

Replace circuit card assembly A6 (para 5-15).

Step 2. Check circuit card assemblies Al, A2, A3 and A7 (para 5-29e, g g and k).

Replace defective circuit card assemblies (para 5-15).

12.

PHASE DISPLACEMENT BETWEEN 250 KHZ SQUARE WAVES MORE THAN 100 NSEC.

Step 1. Check derived timing No. I circuit card assembly A4 by replacement (para 5-15a).

Replace circuit card assembly A4 (para 5-15).

Step 2. Check derived timing No. 2 circuit card assembly AS (para 5-290.

Replace circuit card assembly AS (pan 5-15).

Step 3. Check circuit card assemblies Al, A2, A3, A6 and A7 (para 5-29e, f, g, J, and k).

Replace defective circuit card assemblies (para 5-15).

Step 4. Check + 15 V output of power supply AIPS2 as follows:

(a) Plug STE extender card into connector AS position.

(b)

Check for + 15.0:0.5 V between pin 2 (+) and pin 44 (-) on extender card,

(c)

If voltage is core, continue to step 5.

(d)

If voltage is out of adjustment, adjust AlPS2 (para 5-11).

(e)

If voltage is missing check power supply terminals 7 (+) and 6 (-) for + 15.0:0.5 V. Replace defective power supply (para

5-19).

Step 5.

Check-15 V output of power supply AIPS2 as follows:

(a)

Check for -15.0tO.5 V between pin I (-) and pin 44 (+) on extender card.

(b)

If voltage is out of adjustment, adjust AIPS2 (para 5-11).

(c)

If voltage is missing check power supply terminals 7 (+) and 6 (-) for -15.0:0.5 V. Replace defective power supply O= 5-

19).

5-5