Figure 3-1. Preliminary Troubleshooting Diagram.

TM 11-5820-509-35

Point of

measurement

Normal indication

Isolating procedure

15 ohms

Very low reading, shorted C207, C220, or C234 in FL2, shorted

Between A5J4 and chassis ground.

primary of T3, or short in filament bypass C103, or defective

ac power control relay K2. High reading may indicate open

winding at T1.

Very low reading, shorted filter capacitor C25, C26, C28, or

15 ohms

Between A5J7 and chassis ground.

C29, shorted R14 or defective voltage regulator assembly

TB1. High reading may indicate open inductor L1.

Very low reading, shorted filter capacitor C27, transistor Q3, or

Between A5J8 and chassis ground.

30 ohms

short in other modules. High reading defective voltage

regulator assembly TB1.

Very low reading, shorted filter capacitor C25, C26, C28, or

Between A5J9 and chassis ground.

8 ohms

C29, shorted R14 or defective low-voltage rectifier CR26

through CR29. High reading, open inductor L1.

A low reading may indicate a short on the 115-volt, 400-

Between A5J10 and chassis ground

Infinity

Hz.primary power source..

A low reading may indicate a short on the 115-volt, 500-Hz

Between A5J11 and chassis ground

Infinity

primary power source.

A low reading: shorted filter capacitor A6C37, A6C36, bypass

Between A6J2 and chassis ground.

200 ohms

capacitors A7C4, A7C9, A7C20, A2C19. High reading may

indicate open inductor A6L9.

Figure 3-1. Preliminary Troubleshooting Diagram.

3-4