How to Replace the Fan in a QSC K10 Loudspeaker

My QSC K10 loudspeakers were purchased in 2010. Thirteen years later (wow, where did the time go!?!?), the fans are starting to make loud grunting noises. Anyway, time for a replacement!

Electrical and other Safety:

Technology and the laws and limitations imposed by manufacturers are constantly changing. Thus, some of the projects described may not work, may be inconsistent with current laws or user agreements, or may damage or adversely affect some equipment, or may void your warranty!

Your safety is your own responsibility, including proper use of equipment and safety gear, and determining whether you have adequate skill and experience. Power tools, electricity, and other resources used for our projects are dangerous, unless used properly and with adequate precautions, including safety gear. If you are a younger person or are inexperienced with electrical devices, ask for help from a licensed professional.

You must accept that You and You Alone are Responsible for your safety and safety of others in any endeavor in which you engage. While the material presented here is provided in hopes that you repaire your own system, You are Responsible for verifying its accuracy and applicability to your project. You are Responsible for knowing your limitations of knowledge and experience. If you are not comfortable working around power wiring, you should consult a Licensed Electrician.

Some illustrative photos do not depict safety precautions or equipment, in order to show the project steps more clearly. These projects are not intended for use by children. Use of these instructions, kits, projects and suggestions is at your own risk. We disclaim all responsibility for any resulting damage, injury, or expense. It is your responsibility to make sure that your activities comply with applicable laws.

Required

• A new fan! I bought mine off eBay for just $3.50 shipped (versus $20+ speaker shops charge). Search eBay for "1PCS COOL TRON FD5010S12W7-71 12V 2.10W silent cooling fan 5CM". I purchased three total -- two for replacements and one to keep as a spare.
• #2 Phillips screwdriver (the longer, the better)
• 7/32" socket and driver
• Wire cutters/snips
• Small zip ties

Recommended

• Battery-powered drill driver with #2 Phillips bit and extension
• Nitrile gloves
• Small towel
• Small plastic pry tool
• Toothpick, tweezers or jeweler's screwdriver

Optional

• Red Loctite

Place the speaker face down on a solid surface.

Using a #2 Phillips screwdriver, remove all 12 screws surround the rear panel.

Remove all 11 screws around the rear ports.

Using a small plastic pry tool, (or just your fingernails), gently pull knobs straight out. It may require a light rocking motion to loosen them up.

Insert your fingers into the holes left by the knobs and gently pull the rear panel straight up.

Using wire cutters/snips, carefully cut the zip tie. Be extra cautious as to avoid damaging the ribbon cable.

Place a small towel over the speaker body to avoid scratches from the removed parts.

TO AVOID POSSIBLE ELECTRIC SHOCK, DO NOT TOUCH ANYTHING BELOW THE POWER SUPPLY COVER OTHER THAN WHAT IS OUTLINED IN THE FOLLOWING STEP(S). WEARING LATEX OR NITRILE GLOVES IS RECOMMENDED FOR THIS STEP.

Remove the 4 screws holding the power supply cover.

TO AVOID POSSIBLE ELECTRIC SHOCK, DO NOT TOUCH ANYTHING BELOW THE POWER SUPPLY COVER OTHER THAN WHAT IS OUTLINED IN THE FOLLOWING STEP(S). WEARING LATEX OR NITRILE GLOVES IS RECOMMENDED FOR THIS STEP.

• Pulling firmly and straight up, remove the BROWN wire connected to J14.
• Remove the BLUE wire connected to J15.

You now have enough room to safely flip over the rear panel.

Place a small towel over the speaker body to avoid scratches from the removed parts.

Optional: Using a small vacuum, clean out the insides of the speaker. Mine had lots of dust, cat hair, and a dead spider.

Remove the 4 screws holding the amplifier circuit board in place.

Flip over the circuit board to reveal the other side -- including the fan's connector.

Disconnect the fan's connector from the circuit board by pulling straight up.

Using a 7/32" socket, remove all 4 nuts as well as the washers underneath. Mine had 4 small and 4 large washers.

Remove the fan from the rear panel.

The new fan looks slightly different from the old one. Not only are the holes smaller, but the wires are longer and the red/black wires are reversed. I used a zip tie to shorten the wire length.

Using a small pointy object like a toothpick, tweezers or jeweler's screwdriver, I removed the red and black wires and then swapped them.

Insert a new zip tie into the circuit board as shown.

Assembly is simply the reverse process:

1. Reinstall fan to rear panel. (optional: apply red loctite to threads afterwards to seal them)
2. Reconnect fan into circuit board.
3. Reinstall circuit board to rear panel.
4. Reconnect BROWN wire to J14.
5. Reconnect BLUE wire to J15.
6. Reinstall power supply cover.
7. Place ribbon cable into zip tie, trim, and discard excess.
8. Place rear panel back on the speaker.
9. Reinstall 11 screws for rear ports.
10. Reinsall the two knobs.
11. Reinstall 12 screws for rear panel.

Plug in the speaker and turn it on.

After a few seconds, the fan should start spinning COUNTERCLOCKWISE for about 10 seconds and then it will stop.

Here is a video demonstration (YouTube).

The COUNTERCLOCKWISE motion will pull air INTO the loudspeaker's power supply to help keep it cool. This is what you want.

Optional: Put a label on the speaker so you can log when you changed the fan.

Enjoy your new, silent loudspeaker!