Section V
Model 465A
Figure 5-4 and Table 5-5
FALSE
11
FALSE
TRUE
10
FALSE
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FALSE
FALSE
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465A-B-0218
TRUE
Figure 5-4. Troubleshooting Tree
Table 5-5. Troubleshooting
Remove the + side of C14 from the circuit
board. Set Model 465A GAIN to 40 db.
Apply a 1. 0 mv, 2 kc input signal.
Measure the de voltage at the + side of C20.
Should be +45 v (±1 v). If
proceed to
<ID
;
if incorrect, go directly to
.
Observe the ac waveform at the Model 465A
OUTPUT. Should be a sine wave with peak
voltage of
12.7 v (9 v rms). If
incorrect, proceed to
.
Observe the ac waveform at the base of Q4.
Should be a sine wave with peak voltage of
approximately 12.7 v (9 v rms). If correct,
proceed to
®;
if incorrect, go directly to
@.
Observe the ac waveform at the junction of R24
and R25. Should be a sine wave with peak
voltage
7 v (9 v rms). If
correct, proceed to
;
if incorrect, go directly
to
(1) .
@
Check R26, R27 and C15.
5-6
Check Q4, Q5 and Q6. Refer to Figure 5-8
for typical de voltage levels.
Check Ql, Q2 and Q3. Refer to Figure 5-8
for typical dc voltage levels.
Disconnect jumper wire at the + side of C20,
removing power supply from circuit. Measure
dc voltage at the + side of C20.
be
+45 v(±1 v). If correct, proceed to
;
if
incorrect, go directly to
@ .
Connect a DC Power Supply (-hp- Model 723A)
to the collectors of Q5 and Q6. Connect the
high side to the collector of Q5; the low side
to the collector of Q6. Adjust the power
supply output to +45 v; set current limit to
75 ma. If power supply indicates current
limit, check Q4, Q5, Q6 and CR2-3 for short.
Check Model 465A power supply to include Tl
secondary, Q7, CR6, Q8 and Q9. Refer to
Figure 5-8 for typical dc voltage levels.
01775-1
Содержание 465A
Страница 1: ...465A AMPLIFIER OPERATING AN D SERVICE MANUAL HEWLETT PACKARD ...
Страница 19: ...Model 465A C 22 _ _ l_ Q9 465A B 0219 01775 1 Figure 5 5 Top View Section V Figure 5 5 _ TI 1 _ _ CI5 5 7 ...
Страница 20: ...Section V Figure 5 6 465A A 0220 5 8 Figure 5 6 Printed Circuit Board Parts Location Model 465A 01775 1 ...
