Figure 4 - BPA-125 Rear Panel Connection Diagram
THERMAL BREAKER.
If the thermal breaker opens, there will be
no audio output; however, the power switch lamp will remain illu-
minated. Wait approximately two minutes for the breaker to reset. If
it resets and then opens again, investigate the cause of the
temperature overload. This may be due to improper connections at
the output terminals or to excessive environmental heat with inade-
quate ventilation. The thermal breaker will open when the
temperature at the output transistor heat sink reaches 105 °C.
CIRCUlT BREAKER.
If the AC circuit breaker opens, the power
switch lamp wiIl go out and the amplifier will have no output;
however, there will be power at the AUX POWER receptacle on the
rear panel. Set the POWER switch to OFF and momentarily depress
the red button on the circuit breaker to reset it. Return the POWER
switch to ON. If the circuit breaker trips again, do not attempt to
reset it; have the trouble investigated by a qualified technician.
MAINTENANCE
CAUTION
There are no user-serviceable parts within the
amplifier. Have all internal servicing performed by a
qualifed technician. The warranty will become void if
repairs are made by other than the Bogen Service
Department or authorized service agency.
BOGEN SERVICE
Our Service Department is interested in the maintenance of
your Bogen equipment. If trouble ever develops, do not hesitate
to ask our advice or assistance. Information may be obtained by
writing to: Service Department, Bogen Division, P.O. Box 500,
Paramus, N.J. 07653.
When communicating with us, give the model and series
designation of your unit. Describe the difficulty and include
details on the electrical connections to associated equipment,
such as preamplifiers, speakers, etc. We will send you service in-
formation if the trouble appears simple. If the amplifier requires
servicing, we will send you the name and address of the nearest
authorized Bogen service agency.
When shipping the amplifier, pack it well, using the original
shipping carton or similar container and filler material to prevent
damage in transit.
Remove any plug-in transformer from the
printed circuit board beforeshipping.
Send the unit, fully insured
and freight prepaid via UPS or other responsible carrier. The
repaired unit may be picked up by you personally or will be
returned to you freight prepaid while in warranty.
REPLACING COMPONENTS
All semiconductor components on the printed circuit board
are soldered in place to ensure maximum reliability. When
soldering or unsoldering transistors and diodes, use a heat sink
(such as a small alligator clip) between the source of heat and the
component. When replacing driver and output transistors, be
certain to install the case/heat sink insulator, after lightly coating
both sides with a thermal conducting compound (such as Dow
Corning No. 340, or equivalent).
R E P L A C E M E N T P A R T S
Most components used in the amplifier are standard parts
available through reputable parts suppliers. The parts listed here
may be obtained through Bogen distributors, service agencies or
directly from the factory. When ordering a part, specify the part
number and the description, as listed. Specify the model of the
unit and give the series designation, which is a letter followed by
numbers, located on the rear panel. For parts on the circuit
board, also give the component board assembly number, which
begins with “45”.
