Tech Tips - Infinity BU-120 Service Manual

Amplifier/Subwoofer
Troubleshooting tips and solutions to common service problems
For models: BU-120/HTS-20
TIP# INFTT2000-01
Complaint:
How do you replace or service any of the front panel components on the Subwoofer faceplate for model
BU-120/HTS-20.
Probable Cause:
The High level Input terminals, potentiometers, RCA jack, and switch(es) are behind a sealed cover to protect the
air-tight integrity of the cabinet enclosure.
Solution:
1) Unplug all external cables from the subwoofer; place the cabinet on a padded surface.
2) Remove any subwoofer grille; remove the woofer from the cabinet. Detach the two connections from the
woofer terminals.
3) Remove all Phillips screws holding the amplifier to the cabinet; remove the amplifier.
4) Remove all knobs, nuts, and Philips screws from the outer control section of the amplifier faceplate.
5) Locate the sealed cover on the inside of the amplifier faceplate (see illustration); the bead of adherent must be
broken to remove the main PCB with front panel components from the plastic faceplate. This is most easily
accomplished by CAREFULLY using a box cutter, exacto knife, or similar sharp instrument. First scrape all
excess material from the three surfaces; then force the blade into the groove between the rear cover and the
faceplate. DO NOT attempt to remove the rear cover from the main PCB.
6) When enough material is removed, the main PCB with cover should pull away from the faceplate, exposing
the components.
7) After servicing a bead of "silicon seal" or similar adherent must be applied to all surfaces where it was
removed. Reassemble the rest of the components in reverse order.

TECH TIPS

BU-120/HTS-20
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