Subwoofer power LED on but no sound.

Question

Car Subwoofer Repair

A general-purpose audio device that transmits low audio frequencies to your ears.

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tr121 @tronke

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crwdns2931729:0crwdne2931729:0: Mud 12, 2020

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Subwoofer power LED on but no sound.

Narrowed issue down to subwoofer after trying multiple cables to connect AV receiver to subwoofer and changing a few settings on the AV receiver itself. Before I go inside and see if anything is clearly damaged are there any other good troubleshooting tips, and is there anything I should be aware of before opening the subwoofer up?

Subwoofer model is an Infinity SUB750 connected to a Pioneer Elite EX-500 AV receiver (silver one, not the black one).

EDIT:

Do I have the multimeter on the right setting? And how do I plug the multimeter in properly with these pointy ends?

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Sometimes The subwoofer has a subwoofer volume rocker, make sure it's set for playing subwoofer sound's.

crwdns2934271:0Yan 27, 2024crwdnd2934271:0 JAson WHLan crwdne2934271:0

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jayeff @jayeff

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crwdns2931729:0crwdne2931729:0: Mud 13, 2020

crwdns2933897:0crwdne2933897:0

Hi @tronke ,

Have you proved that there is output from the receiver to the sub woofer?

Try connecting a DMM (digital multimeter) set to 20V AC scale to the receiver's SW output and check for a reading when playing audio which would use the SW

It most probably will be less than 20V but just selected that as a safe starting point.

You could also try low frequency response headphones and check if you hear it at the receiver as well, but the meter is more conclusive if you're not sure about the headphones' response to low frequencies.

Just a thought.

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@jayeff I have not, and I will try it tonight. Thank you for your insights!

crwdns2934271:0Mud 18, 2020crwdnd2934271:0 tr121 crwdne2934271:0

@jayeff Edited my answer, I’m obviously a little new at this stuff so bear with me

crwdns2934271:0Mud 20, 2020crwdnd2934271:0 tr121 crwdne2934271:0

Hi @tronke ,

No.

You have it set on 20V DC not AC. AC is denoted by ~ symbol

Unfortunately your DMM has only two AC voltage options 200V and 600V

You can try the setting as shown in your image but the reading won't be accurate.

See what it displays when using the 200V AC setting.

Connect the meter across the the connector where the cable to the sub woofer plugs into the receiver.

There should be two connection points in the 1 socket 1 inner and 1 outer if it is an RCA type socket.

With AC it doesn't matter which probe goes on which connection.

Just make sure that the meter probes do not touch each other or bridge from one connector to the other shorting it out.

I'm assuming that the receiver will still output to the SW even if there is no cable connected.

crwdns2934271:0Mud 20, 2020crwdnd2934271:0 jayeff crwdne2934271:0

Hi @jayeff it's been a bit but I have an update. I bought a cheap subwoofer off of Amazon and it turns out the subwoofer is the issue and not the AV receiver. The subwoofer is quite nice and I'd hate to throw it out... what could I do to possibly repair the subwoofer? I forgot to mention this when I posted the thread originally but "power LED but no sound" means the status LED lights up and turns red but does not turn green when some music is playing.

crwdns2934271:0Sun 20, 2021crwdnd2934271:0 tr121 crwdne2934271:0

Hi @tronke ,

It means that the woofer is not detecting the signal input even though it’s powered on.

You would need to openthe woofer and check the boards for any damage and also verify that all the voltage supply rails on the woofer circuit board are OK

Here’s the service manual which may help. Be patient when going to download it, as it takes a little while to go from “processing” to "download", after you have passed the security check and then clicked on Go to Download below the Document preview box.

The manual has the wiring diagrams and also shows how to test the woofer on p.10 but you need a bit of equipment to do this.

crwdns2934271:0Sun 20, 2021crwdnd2934271:0 jayeff crwdne2934271:0

crwdns2934285:0crwdne2934285:0

Sometimes The subwoofer has a subwoofer volume rocker, make sure it's set for playing subwoofer sound's. — JAson WHLan
@jayeff I have not, and I will try it tonight. Thank you for your insights! — tr121
@jayeff Edited my answer, I’m obviously a little new at this stuff so bear with me — tr121
Hi @tronke ,

No.

You have it set on 20V DC not AC. AC is denoted by ~ symbol

Unfortunately your DMM has only two AC voltage options 200V and 600V

You can try the setting as shown in your image but the reading won't be accurate.

See what it displays when using the 200V AC setting.

Connect the meter across the the connector where the cable to the sub woofer plugs into the receiver.

There should be two connection points in the 1 socket 1 inner and 1 outer if it is an RCA type socket.

With AC it doesn't matter which probe goes on which connection.

Just make sure that the meter probes do not touch each other or bridge from one connector to the other shorting it out.

I'm assuming that the receiver will still output to the SW even if there is no cable connected. — jayeff
Hi @jayeff it's been a bit but I have an update. I bought a cheap subwoofer off of Amazon and it turns out the subwoofer is the issue and not the AV receiver. The subwoofer is quite nice and I'd hate to throw it out... what could I do to possibly repair the subwoofer? I forgot to mention this when I posted the thread originally but "power LED but no sound" means the status LED lights up and turns red but does not turn green when some music is playing. — tr121
Hi @tronke ,

It means that the woofer is not detecting the signal input even though it’s powered on.

You would need to openthe woofer and check the boards for any damage and also verify that all the voltage supply rails on the woofer circuit board are OK

Here’s the service manual which may help. Be patient when going to download it, as it takes a little while to go from “processing” to "download", after you have passed the security check and then clicked on Go to Download below the Document preview box.

The manual has the wiring diagrams and also shows how to test the woofer on p.10 but you need a bit of equipment to do this. — jayeff

Car Subwoofer Repair

Subwoofer power LED on but no sound.

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