CE Series Service Manual
Rev. D
Red/White
Red/White
White
White
1
2
3
4
White
White
125613-1
Service
4-pin header from
Transformer
Red/White
Red/White
BGS VGS
Error
Amplifier
-
+
-
+
+
-
Signal
Translator
LVA
Positive
Driver
Stage
Bias
Servo
Positive
Output
Stage
Protection
Circuitry
Positive
Driver
Stage
Positive
Output
Stage
Negative Feedback (NFb)
Amplifier
Output
Audio
Input
Mute
Circuitry
tempting to make very precise THD or noise measure-
ments, the main module must be completely installed in
the chassis with all seven mounting screws properly seated
to their specified torque, 12-14 in-lb (1.35-1.58 newton
meters). This assures a proper low-impedance ground
path for the module. However, if you require measuring
THD or noise with the main module removed from the
chassis, please call technical support for further informa-
tion and instruction.
If you are attempting to check or measure VI limiting, out-
put power, or any other test which would require the ampli-
fier to produce large amounts of heat, the main module
should be securely mounted inside the chassis with the
fan connected. If the module must be removed from the
chassis, the test should be of very short duration, and/or
an external fan should be used for cooling the heat sinks.
Service Kit Assembly Instructions
1. Follow the main module removal procedure.
2. Attach the 16AWG blue wire in the service kit to the
16AWG blue wire on the main module and to the negative
tab on the rectifier.
3. Attach the 16AWG red wire in the service kit to the
16AWG red wire on the main module and to the positive
tab on the rectifier.
4. Attach the 22AWG white wire in the service kit to the
22AWG white wire on the main module and to the AC tab
on the rectifier.
5. Attach the 14AWG black/white wire in the service kit to
the 14AWG black/white wire on the main module to the
14AWG black/white wire coming from the transformer.
6. Plug in the female 4-pin connector on the 4-wire service
assembly to the 4-pin header on the main board. Plug the
male end into the 4-pin female connector coming from the
transformer, making sure the orientation is as shown in
Figure 2.1. Plug in the input module.
Optional Grounding Wire
7. On the 12AWG green ground wire, attach the longest
wires’ ring terminal to the chassis ground shown in Figure
2.2, using the PWA mounting screw. The remaining three
wires should be attached to the PWA at the three ground-
ing locations shown in Figure 2.2, using the 6-32 screws
and 6-32 hex nuts provided in the kit.
Figure 2.1 4-pin Connector Wiring Diagram.
2.4.2 Initial Conditions
The start of each step assumes all switches are pre-set to
the following positions:
Mode Switch: STEREO position.
Input Sensitivity Switch: 1.4 V position.
Level Controls: Both up (clockwise) fully.
2.4.3 Test Procedure
The following steps are arranged in order for best results
and, for the most part, easiest use. Read each step care-
fully before proceeding. Read all precautions in Section 2.1
before continuing. Use extreme caution and good common
sense at all times. The preceding warnings and cautions
are detailed for good reason.
2.4.4 Service Kit Wire Extensions
A service kit containing wire extensions is available from the
Crown Parts Department (part # 125581-1). By using the
wire extensions provided in the kit, maneuverablility of the
main module is greatly increased. When using the service
kit, it is required that all instructions be followed.
Special Note On Grounding: Whenever the main module is
removed from the chassis and power is applied, the ground-
ing wires absolutely must be attached. Also, if you are at-
WARNING! Most adjustments are made with the cover removed.
Prior to any AC power off testing, discharge all power supply
capacitors. Also, use extreme caution when making internal
adjustments when the unit is powered.
2.4.1 Equipment Required
The following is a list of standard equipment needed to
perform all the tests listed in Section 2.3.3:
Line Voltage Variac: 2-kW or larger.
Oscilloscope: 2 Channel, 10-MHz or better.
Digital Multimeter: Various measurements.
Watt Meter: For AC line draw.
ACVM: Peak reading RMS calibrated (all AC line volt-
age and amplifier output voltage checks).
I.M.D. Analyzer: 60 Hz/7 kHz in 4:1 ratio, accurate to
0.001% I.M.D.
T.H.D. Analyzer: Accurate to 0.001%.
Loads: 2000 W continuous at 1 ohm.
Maintenance 2-3
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