TABLE 4-2. TROUBLESHOOTING CHART (Continued)
Step
Symptom
Probable Cause
Corrective Action
3
(4) Broken wires on 1A8
(4) Replace 1A8 (see paragraph 4-6h.)
(cont'd)
(5) Defective meter CAL adjust
(5) Replace 1A3 (see paragraph 4-6d.)
potentiometer 1A3R3
4
No filament voltage
a. No voltage (ac) at connector 1A3J1
a. Replace 1A2 (see paragraph 4-6c.)
b.
Defective
1A3BR1,
1A3U1
and
b. Replace 1A3 (see paragraph 4-6d.)
associated circuitry
c.
6.3 V ADJ potentiometer 1A3R1
c. Adjust per paragraph 4-7e.)
improperly adjusted
No oscillator power supply
5
a. Faulty fuse 1A4F1
a.
Replace fuse 1A4F1
voltage (+30 V)
b. No ac voltage at connector 1A4J1
b. Replace 1A2 (see paragraph 4-6c.)
c. Defective 1A4BR1, 1A4Q4, 1A4Q5
c.
Replace 1A4 (see paragraph 4-6e.)
and associated circuitry
a, Defective H.V. BOX 1 A 5
6
No beam voltage (-1250V)
a.
Replace 1A5 (see paragraph 4-6a.)
NOTE: Check Steps 7
and 8 as they are inter-
b. Defective 1A4U3
b. Replace 1A4 (see paragraph 4-6e.)
related.
c.
-1250 volts improperly set
c.
Adjust per paragraph 4-7b.
7
No repeller voltage supply
a.
Defective H.V. Box 1A5
Replace 1A5 (see paragraph 4-6f.)
a.
(-1850V)
b. Defective repeller supply regulator
b. Replace 1A3 (see paragraph 4-6d.)
8
N O +40 V supply for
Defective H.V. Box 1A5
Replace 1A5 (see paragraph 4-6f.)
amplifier circuit
9
No or low beam current
a.
Defective operational amplifier 1A5A2U1
a.
Replace 1A5 (see paragraph 4-6f)
b. Beam current improperly adjusted
b. Adjust per paragraph 4-7d.)
