Repairing small desktop PC speaker with very faint audio - possible? Edit: Fixed - Page 1
Forum section: electronics / repair

author: SolderSucker
author_rank: Regular Contributor
timestamp: May 15, 2020, 07:28:54 pm
content: 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.

author: Manul
author_rank: Super Contributor
timestamp: May 15, 2020, 07:54:43 pm
content: 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.

author: cdev
author_rank: Super Contributor
timestamp: May 15, 2020, 07:55:04 pm
content: 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.

author: SolderSucker
author_rank: Regular Contributor
timestamp: May 15, 2020, 08:02:06 pm
content: Quote from: Manul on May 15, 2020, 07:54:43 pmThanks, it seems to feel okay.

author: SolderSucker
author_rank: Regular Contributor
timestamp: May 15, 2020, 08:05:02 pm
content: Quote from: cdev on May 15, 2020, 07:55:04 pmNo 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?

author: cdev
author_rank: Super Contributor
timestamp: May 15, 2020, 08:10:32 pm
content: 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?

author: Manul
author_rank: Super Contributor
timestamp: May 15, 2020, 08:16:16 pm
content: 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.

author: SolderSucker
author_rank: Regular Contributor
timestamp: May 15, 2020, 08:29:11 pm
content: Quote from: cdev on May 15, 2020, 08:10:32 pmYeah, 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?

author: cdev
author_rank: Super Contributor
timestamp: May 15, 2020, 09:52:07 pm
content: 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.

author: amyk
author_rank: Super Contributor
timestamp: May 16, 2020, 03:48:32 am
content: Dirt or some small creature may have gotten the cone stuck, and was dislodged when you disassembled and reassembled it.

author: SolderSucker
author_rank: Regular Contributor
timestamp: May 16, 2020, 09:22:51 am
content: 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?

author: cdev
author_rank: Super Contributor
timestamp: May 16, 2020, 02:15:53 pm
content: 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.

author: Manul
author_rank: Super Contributor
timestamp: May 16, 2020, 02:21:03 pm
content: 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.