TM-9-1240-401-34-P

TELESCOPE MOUNT M146: M118A2 AND M118A3; TELESCOPE MOUNT M145: M145A1; PANORAMIC TELESCOPE: M117 AND M117A2; FIRE CONTROL QUADRANT: M15; PERISCOPE: M42

TECHNICAL MANUAL; DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL

JULY 1993

TM-9-1240-401-34-P - Page 314 of 590

6-4

TM 9-1240-401-34&P

6-8. GENERAL SUPPORT SYMPTOM INDEX

Troubleshooting

Procedure

(Page)

Mounting surface does not seat M42 periscope correctly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4

Windows are broken or cracked . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4

Windows are fogged or condensation is present . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4

6-9. GENERAL SUPPORT TROUBLESHOOTING

MALFUNCTION

TEST OR INSPECTION

LOCATION

CORRECTIVE ACTION

1.

MOUNTING SURFACE (1) DOES NOT SEAT M42

PERISCOPE CORRECTLY.

Observe visually.

a. Clean mounting surface with

cleaning compound (item 3,

appx B).

b. Remove burrs with abrasive

cloth (item 4, appx B) dipped

in cleaning compound (item 3,

appx B).

2. WINDOWS (2) ARE FOGGED OR CONDENSATION IS

PRESENT.

Observe visually.

a. Purge and charge M42 periscope

(TM 750-116).

b. Repair M42 periscope (ref. para 6-10).

3. WINDOWS (2) ARE BROKEN OR CRACKED.

Observe visually.

Repair M42 periscope (ref. para 6-10).