JBL Professional Series - AC Test Voltages Table

Table
II,
AC
Test
Voltages,
provides
the
signal levels
to
be
checked
in
the
order
indicated
at
various
test
points
in
the
mixer.
The
table
includes
a
recommended
procedure if
there
is no
signal
at any
one
or more
of
the
test points.
The
signal
levels
indicated
in
the
table are
based
on an
input
signal of
1000
Hz
at
.5 mV
applied
to any
one of
the
six
microphone
inputs of
the
5306.
AC
Test
Voltages
Amplifier
1
Test
Signal
Stage
Gain
Point
Level
(nom)
Procedure
If
No Signal
Microphone
46dB
1
4.5mV+
10% Check
input
transformer
T501
or
502
Preamplifier
Mic
Control
at
Including
”10"
.1V+ 10%
Check
R107
or R108,
check
transistor
D.C.
Transformer
voltage
(collector
of
Q504
or Q51
1
)
Mixing
Amplifier
17dB; Master
3 .71V+ 20%
Check
R101;
check
transistor
D.C.
Voltage
Control
at
"10"
(collector of
Q403);
check
C402.
Line
Amplifier
23dB
4 .71
V+
20%
Check
C406
5 1
0V
+
20% Check
transistor
D.C.
voltage
(collector
of
Q406 or
Q407);
check
C408
Output
OdB
6 10V
+20% Check
C41
1
Amplifier
Tone
Controls
set
at
"0"
1 0V
+
20% Check
transistor
D.C. voltage
(collector
of Q41
1 or
Q412);
check
C417
10V+
20% Check
C418
B
10V+
20%
Check K401;
check
T302;
check
C425
Monitor
OdB
10
10V+20% Check
C419
Amplifier
Monitor
Gain
1
Control
11
10V +20% Check
R102,
C420
Maximum
12
10V+
20% Check
transistor
D.C. voltage
(collector
of
Q416 or
Q417);
check
C423
13
10V+ 20% Check
C424
14
1
0V
+
20% Check
K401
9