LOUD Technologies SR1521Z Operating instructions

1
SR1521z REPAIR MANUAL

2
These instructions are intended to help restore any ailing SR1521z Active
Loudspeaker back to factory working conditions. They show how to remove and
replace the drivers and the amplifier assembly.
Please contact Mackie Tech Support (1-800-898-3211) to receive a Service
Request Number and Order Number for parts needed for this restoration. They will
also help you determine the nature of the problem and what parts will repair the unit.
Tools needed:
***NOTE: not all tools listed below will be needed for your repair***
• Phillips head screwdriver.
• 3mm, 4mm, and 5mm allen wrench.
• 8mm open end wrench.
• Solid workbench.
• Non-carpeted work area due to static electricity. If available, an ESD mat
(Electro-static discharge) is optimal.
Parts needed:
***NOTE: not all parts listed below will be needed for your repair***
• Led PCB Assembly Part #0007334 pages 3-4
• 15” Woofer Part #0013914 pages 5-6
• High Frequency Driver Part #0008093 pages 7-9
• Diaphragm Part #coming soon pages 10-11
• Amplifier Assembly Part #0014137-00 pages 12-14
Safety Warnings:
• Make sure that you turn off the unit and disconnect the power cord (and all
other cords) before you begin these procedures.
• Always use safety glasses!
• Please try NOT to touch any of the pcb circuitry, capacitors, resistors, etc.
• Take care to read and follow these instructions. It may help to read the
instructions prior to the repair to get an idea of what it entails.
• Before beginning the repair, touch metal to discharge any lingering internal
static electricity.

3
Led PCB replacement:
3
Carefully begin to remove the grill. Do
not fully remove the grill as the cable
is still firmly attached to the led PCB
assembly.
2
Keep the six screws in a safe place.
4
Carefully remove the cable attached to
the led PCB assembly.
1
Three screws need to be removed from
each side of the grill using the phillips
head screwdriver (six screws in all).
5
Use phillips head screwdriver to remove
one screw from center of led PCB
assembly.

4
6
Carefully remove the led PCB assembly
from the back side of the grill. A flat
head screwdriver may aid in removal of
the led PCB assembly if it is sticking.
Led PCB replacement continued:
7
The hard part is done, the rest is easy!
Place the new led PCB assembly (part
#0007334) where the old one was. Follow
the same steps as above, but backwards
6 to 1. Power up the SR1521z and the led
should light up. Congratulations, you just
replaced an led PCB assembly...now go
play some shows!

5
Woofer replacement:
1
Follow steps 1-4 of the led PCB
replacement instructions, as the grill will
need to be removed in order to access
the woofer.
2
Eight screws need to be removed from
the woofer using the 4mm allen wrench.
3
Keep the eight screws and washers in a
safe place.
4
Carefully begin to remove the woofer.
This woofer has a tendency to want to
“pop out,” so please be sure to hold
the woofer in place with your free hand
while removing the screws with the other
hand.
Caution: The woofer is approximately
17 pounds with the weight unevenly
distributed.
8
12
3
4
5
6
7

6
Woofer replacement continued:
6
Remove the cables from their terminals
simply by pushing down on the terminal
and pulling out the cable.
7
This is what it looks like with the grill and
woofer removed. Place the new woofer
(part #0013914) where the old one was.
Follow the same steps as above, but
backwards 6 to 1, making sure to keep
the led PCB assembly cable in front of
the woofer. Power up the SR1521z and
the new woofer should now be pumping
out glorious lows. Awesome, you just
replaced a 15” woofer!
Push
in
5
The positive (solid yellow) and negative
(yellow and black) cables are still
attached to the woofer terminals.
+-

7
High Frequency Driver replacement:
12
3
4
1
Follow steps 1-4 of the led PCB
replacement instructions, as the grill will
need to be removed in order to access
the high frequency driver.
2
Four screws need to be removed from
the horn using the 5mm allen wrench.
3
Keep the four screws and flat washers in
a safe place.
4
Carefully begin to remove the entire
horn assembly (with the high frequency
driver still attached).
Caution: The horn weighs about 5
pounds, and the weight is not evenly
distributed.

8
High Frequency Driver replacement continued:
5
The positive (solid blue) and negative
(blue and black) cables are still
attached to the high frequency driver
terminals. Remove the cables from their
terminals simply by pushing down on the
terminal and pulling out the cable.
6
Four nuts and eight washers may be
removed from the driver using the
8mm open end wrench. Turn counter-
clockwise to loosen and remove,
clockwise to tighten. The other pair is in
the same place on the other side of the
horn assembly.
7
Keep the four nuts, four flat washers, and
four locking washers in a safe place.
8
Lift the horn up as the nuts are loosened.
It cannot be removed otherwise. Notice
that the flat washer is on the bottom,
followed by the locking washer, and
finally the nut.
nut
flat washer locking
washer
+-
Push down

9
High Frequency Driver replacement continued:
9
This is what the high frequency driver
looks like removed from the horn
assembly. Four headless screws need
to be removed from the driver. Pliers
could help if the screws are too tight.
Turn counter-clockwise to loosen and
remove, clockwise to tighten.
12
3
4
12
3
4
10
Keep the four headless screws in a
safe place. Follow the same steps
as above, but backwards 9 to 1.
Power up the SR1521z and the new
driver should now be pumping out
those highs again. Fantastic, you just
replaced a high frequency driver!

10
3
The horn is shown above with the high
frequency driver circled. Four screws
need to be removed from the driver
using the 3mm allen wrench.
12
3
44
Keep the four screws in a safe place.
5
The diaphragm and plate adapter are
easily removed from the horn assembly.
Diaphragm replacement:
2
Follow steps 1-5 of the high frequency
driver replacement instructions, as the
horn will need to be removed in order to
access the diaphragm.
1
At the present time (November 2006),
diaphragms are not currently available,
so you will have to replace the complete
driver following the previous section
(pages 7-9). If you have received a
diaphragm, please follow the steps
below.

11
7
The diaphragm is separated from the
plate adapter simply by pushing down
on terminals.
8
This is what the plate adapter (left) and
diaphragm (right) both look like. Place
the new diaphragm (part # coming
soon) where the old one was. Follow the
same steps as above, but backwards 7
to 1. Power up the SR1521z and the new
diaphragm should now be pumping
out those highs again. Sweet, you just
replaced a diaphragm!
Diaphragm replacement continued:
6
This is what the horn assembly looks like
with the diaphragm and plate adapter
removed. When replacing the new
diaphragm, be sure to line up the holes
correctly. Notice where the terminal
connections fit (circled above).

12
Amplifier Assembly replacement:
1
Fourteen screws need to be removed
from the amplifier assembly using the
phillips head screwdriver. The amplifier
assembly is capped by two cover plates
(part #33901380) outlined above.
8
12
3
4
5
6
7
9
11
10
12
13
14
3
The covers may be worked loose by
wedging a flat head screwdriver in
between the cabinet and the cover, as
well as the amp assembly and cover.
Make sure to get around the entire cover
plate in order to liberate them.
2
Keep the 14 screws in a safe place.

13
Amplifier assembly replacement continued:
4
Once the two cover plates are removed,
two more screws need to be taken out in
order to separate the amplifier assembly
from the cabinet. Keep the two screws in
a safe place.
1
25
The amplifier assembly is now ready to
be separated from the cabinet. Do not
completely take the amplifier assembly
off yet, as five cables need to be
removed first (as shown above).
Caution: The amplifier assembly is
approximately 20 pounds, so please
make sure to grasp it firmly.

14
8
Place the new amplifier assembly
(part #0014137-00) where the old one
was. Follow the same steps as above,
but backwards 7 to 1. Remove the
serial number from the faulty amplifier
assembly (as shown in picture above)
and place on the new amplifier
assembly. Power up the SR1521z and
relish in the fact that you just replaced
an amplifier assembly. Hats off to you for
a job well done!
6
Five cables need to be removed from
the amplifier assembly: (1) solid yellow,
(2) yellow and black, (3) solid blue, and
(4) blue and black. The fifth cable (led
PCB cable) is shown in step 7 below. Do
not force cable removal or connection,
although needle-nose pliers may aid in
loosening the crimped cables.
Amplifier assembly replacement continued:
1 32 4
7
The led PCB cable is shown above. The
black wire of the cable is closest to the
edge of the amplifier assembly. The
cable only fits in one way.
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Important:The faulty amplifier
assembly must be returned to LOUD
Technologies. The address should
be on the return shipping label that
was provided with the new amplifier
assembly. If not, the return address is at
the top of this page. Also, please write
the order number and service request
number (ex: 1046256-1203935) in big,
black, bold numbers on the outside of
the box. This helps expedite the return.