Crown PSA-2 Service Manual

crown
SECTION 7
MAINTENANCE
Ta
Section 7 contains technical information required to
effectively and efficiently service and repair the Crown
PSA-2/SA2 power amplifier. Included are disassembly
and reassembly procedures, required test equipment lists,
checkout procedures, basic troubleshooting tips and a
soldering technique review.
Introduction
THIS INFORMATION IS INTENDED FOR USE BY
AN EXPERIENCED TECHNICIAN ONLY!
Use this information in conjunction with the Instruction
Manual, schematic/board layout diagrams, parts lists
and exploded view drawings (the latter located in Section
6 of this manual).
Capable of displaying a
10MHz signal
Oscilloscope
Volt-ohmmeter
(VOM)
Low-voltage resistance probe
(100mv range). High-voltage
resistance probe (1.5V range)
Freq. Counter
Signal Generator Sine/ Square wave available;
flat frequency response. THD.
1% maximum
Circuit Breaker 15 ampere rating
AC Line Voltage
Monitor
Peak reading meter (displays
rms equivalent to a sinu-
soidal peak from any wave
form)
7.2 Required Test Equipment
Many of the service and repair problems with the PSA-
2/SA2 can be performed with a limited amount of test
equipment. However, in order to return the unit to its
“factory new” specifications, the following list of
required test equipment is recommended. The
“Requirements” column provides information to allow
intelligent selection of substitutes if the “Suggested
Supplier and Model” is not available or is considered
impractical to obtain.
Whenever possible, avoid ground loops in the test
equipment caused by connecting the output ground to
the input ground. Never connect the ground of the cable
going to the load back to input ground. Ground loops are
Telequipment DS54A or
equivalent
Monitoring output during
service and testing
Check resistance values (low
voltage probe). check semi-
conductor junctions for
opens or shorts (high volt-
age probe) Check DC
voltages
Triplett 601 or
equivalent
For accurate general Heath SMII8A
monitoring
Wavetek 130-Series or
equivalent
Provide test signals for
service and checkout
In AC line to unit;
protects circuitry from
overload if power supply
has shorted
Monitor Line voltage Available from CROWN

Crown PSA-2 Specifications

General

Brand	Crown
Model	PSA-2
Category	Amplifier
Language	English