3. For each side of the enclosure, apply a few drops of Loctite 222 on the threads of each of the four
threaded inserts in the enclosure that mate with the panel screws in the rigging assemblies.
4. From the front of the array, slide the replacement enclosure in between its two rigging assemblies.
5. Engage the panel screws released in step 1 and tighten them securely (torque to 46 kg-cm/39.9 lb-in).
9.3.2
TRANSDUCERS
A faulty transducer will usually cause readily audible distortions or other unwanted noises. In other
cases, they may stop functioning. Use your ears and test signals or other sound source to determine
which one is at fault.
Field Repair:
Transducers are field replaceable with factory-supplied replacement parts.
9.3.3
INTERNAL ELECTRONICS AND WIRING
Faults with these items will usually cause transducers to stop working, have significant amounts of
distortion or possibly be intermittent. If the fault is isolated to the internal electronics or wiring, repair
of such faults must be done by the EAW factory service or by an authorized EAW distributor.
Field Repair:
The entire electronics assembly is replaceable with a factory-supplied assembly.
9.3.4
REPLACEMENT FUSE
115V: LOUD P/N 0018783
Slow blow 6.3 A 5 mm x 20 mm 250 VAC (Wickmann P/N 1811630.000; also Littelfuse P/N 21506.3P)
230V: LOUD P/N 0021289
Slow blow 3.15 A 5 mm x 20 mm 250 VAC (Wickmann P/N 1811315.000; also Littelfuse P/N 2153.15P)
9.3.5
ENCLOSURES
Enclosure problems, such as loose hardware, faulty joints, or other structural problems, will usually be heard
as distinct buzzes, rattles, or other unwanted noises. To test for enclosure problems, use a sine wave signal
manually swept on the LF sub-system. The input level should be no more than 6 dB below rated power (equals
no more than 1/2 rated voltage). It may be possible to field-repair some enclosure problems.
Page
21
Figure 4 Remove and Replace Amplifier From the NTL720 Enclosure
AMPLIFIER ASSEMBLY
THE AMPLIFIER’S ELECTRONIC CONNECTORS
ARE DESIGNED TO MATE WITH THEIR
COUNTERPARTS IN THE ENCLOSURE.
UPON REINSTALLATION THE AMPLIFIER WILL
SLIDE INTO THE ENCLOSURE UNTIL ITS
SURFACE IS FLUSH TO THE ENCLOSURE.
IF THE AMPLIFIER IS INSTALLED UPSIDE DOWN
IT WILL NOT SLIDE TO A FLUSH POSITION,
BUT WILL STOP 1/4 INCH ABOVE FLUSH,
DO NOT FORCE AS THIS WILL DAMAGE THE
INTERNAL CIRCUIT BOARD AND CONNECTORS.
6X SCREWS
FLAT HEAD
PHILLIPS DRIVE
TORQUE TO 23 kg-cm [20.0 lb-in.] AND
APPLY LOCTITE 222 ON REASSEMBLY.
Summary of Contents for N T L 7 2 0
Page 1: ...N T L 7 2 0 L O U D S P E A K E R O W N E R S M A N U A L...
Page 2: ...ii...
Page 34: ...Page 28...
Page 35: ...Page 29...
