Audiolab 8000S Service Manual page 9

4.0 f u n c t i o n a l t e s t s
4.2 Functional test procedure
For test point (TP) references, see section 6.0 Test Points.
No Action
4.2.18. Measure offset
of protection
circuit
4.2.19. Disconnect DC
power supplies
4.2.20. Fix any faults
4.2.21. Connect
amplifier to AC
power input
4.2.22. Measure left
channel supply
rails
4.2.23. Measure right
channel supply
rails
4.2.24. Check
operation of
mute relay
4.2.25. Check
preamplifier
supply rails
4.2.26. Left channel
Check power
amplifier
Test Equipment Details
Multimeter set to Connect positive probe to cathode of D943
mV DC (TP
Voltage should be <5 mV.
If any faults have been detected, repair and
return to the beginning of this test
procedure.
Multimeter set to Measure volatge across D713
V DC TP 1-)
Volatge should be 44 V ± 2.5 V.
Multimeter set to Measure volatge across D813
V DC TP 3-)
Volatge should be 44 V ± 2.5 V.
Multimeter set to Connect negative probe to 0 V
V DC Connect positive probe to cathode of D951
(TP
Switch on AC power button.
Voltage should increase slowly from 0 to
12 V then relay should operate and voltage
should increase to 41 V ±2 V.
Multimeter set to Connect negative probe to 0 V
V DC Connect positive probe to 30 V test point
(TP
Connect positive probe to 10 V test point
(TP
Voltage should be 10 V ±0.5 V.
Connect positive probe to 5 V test point
(TP
Voltage should be 5 V ±0.3 V.
Multimeter set to Measure voltage across R731
V DC (TP 5+ and TP
Voltage should be 0.85 V ±0.1 V.
Measure voltage across R735
(TP 6+ and TP
Voltage should be 0.85 V ±0.1 V.
11).
and D714 (TP 2+ and TP
and D814 (TP 4+ and TP
23).
19). Voltage should be 28 V ±3 V.
15).
16).
5-).
6-).
(TP 1+ and
2-).
(TP 3+ and
4-).
(TP 0).
(TP 0).
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