Infinity Overture 1 - Fuse Replacement Procedure

Service bulletin INF9704 - Nov. 1997
To: All Infinity Service Centers
Models: Overture 1; Overture 2; Overture 3
Service Bulletin
Subject: Premature muting
At the moment the bass information at the audio input terminals exceeds 30 mV, the amplifier in the Overture series
switches from the STANDBY mode to the ON mode. Approximately 10 minutes after the bass information drops
below the sensing threshold, the subwoofer amplifier retums to STANDBY.
Some customers may experience a tendency for the Overture 1, 2 or 3 to “mute” or shut down when played at a
low level and negligible bass information is present. Actually, this is normal behavior for the loudspeaker. /f the
unit was designed to be extremely sensitive, the bass amplifier could sense small amounts of 60 Hz hum or noise
picked up by the customer's input cables, random RF noise, etc. and the unit would never tum off.
In the event you receive a Overture 1, 2 or 3 with the complaint “unit is shutting off (muting) when low
levels of music are being played”, this complaint can be resolved by the replacing C20 (220uf/25v) on the
PCB with a 2200uf/25v capacitor.
This change will lengthen the delay time for muting to 50-60 minutes.
Procedure, Overture 1:
1) With a sharp instrument, carefully pry out and remove the metal grille covering the woofer, taking note of the
(4) rubber corners on the grille.
2) Pull back the circular rubber flap and remove the (6) woofer mounting screws and their clamps.
3) Remove the woofer from the cabinet by pulling on the rubber flap, then unplug the yellow connecting wires.
4) Remove the dacron section from the cabinet.
5) Outside the cabinet, remove the (2) Phillips screws on the cabinet end, amplifier side.
6) Inside the cabinet, remove the (2) amplifier mounting nuts. These may be covered with a sealant and will
have to be cleaned off before removal.
7) Unplug the (2) white wires w/spade terminals connected to the crossover assembly.
8) Remove the amplifier assembly from the cabinet.
9) Unplug the AC input wires; remove the transistor clamp and the two mounting nuts from the PCB.
10) Locate C20 (See Figure 1). Remove and replace with 2200uf/25v capacitor (Infinity part # 201-8120).
11) Replace the PCB in the heatsink, taking care to replace the insulating fishpaper under the PCB and the
output transistors.
12) Re-assemble and replace the amp assembly into the cabinet in reverse order, taking special precautions:
a) There are two gaskets under the woofer basket, assure they are both in place upon re-assembly.
b) The (6) clamps under the woofer mounting screws are not symmetrical; make sure the shorter side of
the clamps are pointing towards the center of the woofer cone.
c) Tighten the (6) final woofer mounting screws sequentially; do not over tighten.
d) Before replacing the metal grille, place the rubber corner(s) on each corner of the grille.
FIGURE 1
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Infinity Systems, Inc. 250 Crossways Park Drive, Woodbury, New York 11797 (516) 496-3400 L,