Tannoy SENSYS DCC, Service Manual

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FOR GUIDANCE
Diagnosis of low frequency driver failures resulting from
misuse:-
SYMPTOM PROBABLE CAUSE
Charred voice coil Under powered amplifier clipping; Excessive peak amplifier
power; DC at amp output (amp failure)
F u s e d , b r o k e n o r b l a c k e n e d l e a d o u t w i r e s
Under powered amplifier clipping; Excessive peak amplifier
power; Excessive low frequency equalisation applied
Voice coil out of gap
Excessive peak amplifier power; Excessive low frequency
equalisation applied
Coil rubbing
Excessive continuous amplifier power resulting in separation of
coil former from cone or suspension; Coil delamination due to
excessive temperatures generated; Improper mounting of driver
resulting in deformation of frame; Dropping of cabinet resulting in
deformation of frame or shifted pole piece
Broken frame or misaligned magnet assembly Dropping of cabinet ; careless transportation
Torn or punctured cone Excessive low frequency equalisation applied; Excessive peak
amplifier power; vandalism
Cone to coil joint failure Excessive low frequency equalisation applied
Suspension to coil/cone joint failure Excessive low frequency equalisation applied
Diagnosis of high frequency driver failures resulting
from misuse:-
SYMPTOM PROBABLE CAUSE
Charred voice coil Under powered amplifier clipping; Excessive peak amplifier
power; DC at amp output (amp failure)
Fused or broken leadout wires Excessive amplifier power; connection to low frequency or
midrange amplifier in active system
Leadout to coil joint failure (solder) Excessive amplifier power generating excessive temperatures
which melts solder >300
° C
Coil rubbing Excessive continuous amplifier power resulting in separation of
coil former; Coil delamination due to excessive temperatures
generated; Improper replacement of diaphragm assembly;
Dropping of cabinet resulting shifted pole piece
Diaphragm cracked or pulverised Excessive continuous amplifier power (often frequency related);
Under powered amplifier clipping; Connection to low frequency
or midrange amplifier in active system.
Misaligned magnet assembly Dropping of cabinet ; careless transportation
Diagnosis of manufacturing defects:-
DEFECT TEST RESULT
Insufficient glue on:-
Cone to coil/suspension
Cone to surround
Surround to frame
Suspension to frame Sine wave sweep Buzzing sounds due to separation of
defective joints
Incomplete bonding of voice coil to
diaphragm or insufficient glue on rubber
surround to phase corrector joint Sine wave sweep Buzzing sounds; Coil rubbing; Separation
of the coil from the diaphragm
Dry solder joints on leadouts DC resistance of voice coil termination Coil resistance greater than the rated
impedance, or open circuit
Faulty welds at the voice coil terminations
on the coil former DC resistance of voice coil termination Coil resistance infinite or intermittent
Poorly assembled driver Visual check
Sine wave sweep Buzzing sounds; Loose parts; Coil
rubbing; foreign particles in magnetic gap
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