Repairing small desktop PC speaker with very faint audio - possible? Edit: Fixed

[SolderSucker]

My laptop's pair of external speakers have inside them small speakers like this one:

https://uk.rs-online.com/web/p/speaker-drivers/4318608/

One has just started to produce only very faint audio (it was working fine earlier). It's definitely the speaker at fault, not the cabling or the laptop, connector, etc. I can't find any obvious problems when examining it, measuring resistance, etc. Is this repairable, and if so how? I've never tried to repair a speaker before so this could be a useful learning exercise.


Edit: Update - somehow it's fixed itself. It sounds fine now and I did nothing besides remove it from the enclosure and put it back in again after testing it a few times.

[Manul]

If resistance of the coil is ok, the only way to have faint sound is if it is mechanicaly stuck. But I guess it is not very common. If you gently push speaker's diaphragm with your fingers, does it feel stuck? Do not push a lot, just +-3mm or so. Try to push straight, near center, with two fingers symetrically.

[cdev]

 When you plug in headphones, do both ears get sound? Maybe the headphone jack needs cleaning..

 You should be able to determine with an ohmmeter and another speaker whether the computer or speaker is at fault. Speakers rarely just go bad unless they have been abused badly. Make sure its the speaker and not simply not enough signal making its way too it for some other reason. If the speaker indeed is no longer working unless you can see some problem visually, I would try to find a replacement. Make sure you get the phasing right.

[SolderSucker]

If resistance of the coil is ok, the only way to have faint sound is if it is mechanicaly stuck. But I guess it is not very common. If you gently push speaker's diaphragm with your fingers, does it feel stuck? Do not push a lot, just +-3mm or so. Try to push straight, near center, with two fingers symetrically.

Thanks, it seems to feel okay.

[SolderSucker]

When you plug in headphones, do both ears get sound? Maybe the headphone jack needs cleaning..

 You should be able to determine with an ohmmeter and another speaker whether the computer or speaker is at fault. Speakers rarely just go bad unless they have been abused badly. Make sure its the speaker and not simply not enough signal making its way too it for some other reason. If the speaker indeed is no longer working unless you can see some problem visually, I would try to find a replacement. Make sure you get the phasing right.

No problem with headphones, it's definitely the speaker that's at fault. I guess I'll just have to buy the replacement from RS.

I'll also add that some time ago I had another 'go bad' in the sense that the audio suddenly became very spitty and crackly - I replaced just the internal speaker and could find nothing wrong with the faulty one. What would cause a fault like that?

[cdev]

An intermittent break in the wire? If you replace the speaker it may not work or if it works the micro break may still be there, just folded in such a way its not open now. I would look at the tiny wire and maybe it's what needs replacing.

What happens when you hook up another speaker to the output wires? Is everything okay?

[Manul]

Well, maybe coil got loose... It is glued on a cylinder which goes around magnet. But really that would be unusual and manifest itself not as a faint sound, but as a faint + horrible vibrating and distorted sound.

[SolderSucker]

An intermittent break in the wire? If you replace the speaker it may not work or if it works the micro break may still be there, just folded in such a way its not open now. I would look at the tiny wire and maybe it's what needs replacing.

What happens when you hook up another speaker to the output wires? Is everything okay?

Yeah, another speaker hooked up to the wires works just fine. 

However, here's an interesting development ........ it's just started working again! No idea why, besides taking apart the enclosure and putting it back together nothing has changed!

How's that for a puzzle?

[cdev]

One of the two wires connecting the speaker has a small break in it. I would just replace both of them with two other similar thin wires and be done with it.

[amyk]

Dirt or some small creature may have gotten the cone stuck, and was dislodged when you disassembled and reassembled it.

[SolderSucker]

Thanks.

Well it's still working ........ most peculiar.

How about the other speaker that I had go 'bad' in the sense that the audio became very spitty and crackly? I still have that around somewhere, what would cause that kind of fault?

[cdev]

The speaker you replaced is likely perfectly fine.

If I were you I would replace both wires, otherwise its likely to fail at some time in the future, right when you need to make a presentation with it.

[Manul]

About the other speaker. If it is "crackly", then it may be metal particles stuck on the magnet preventing smooth coil movement, diaphragm getting out of center, coil itself getting loose or intermittent wire connection.