Laptop (Thinkpad edge S430) speakers popping and no sound output except for headphones

[___]

Hey people, maybe someone has a tipp for troubleshooting this.

While watching the pyra/EvilDragon Q&A livestream, my laptops sound suddenly started to stutter. It was like intermittent interrupts, every half second or so. I thought it was a streaming problem at first and switched to another PC with ethernet instead of wireless.

Now that I tried using my laptop again yesterday, I noticed my sound wasn't working at all and I was getting constant popping out of the speakers, even directly after POST when no kernel or anything was active. At first I thought something would be amiss with my alsa config, but since the popping start right after the laptop POSTs I am now certain it's a hardware problem.

Something with the DAC has to have given up the ghost. I am thinking it tries to reach a certain voltage and can't because some capacitor might have blown or something along the lines of that.

The headphone port works flawlessly and if I plug something in, the popping stops and is not heard in the headphones which makes me think it's something to do with the amplifier for the speakers and when it switches to line level audio everythings fine.

Any of the electronically inclined here have a hint for what to measure or look for? All I can find googling are related to driver issues (mostly windows crap)...

 

[FBnil]

Hmm... with pulseaudio, you could disable the speakers and only keep the headphone.

This might work for Alsa:
https://bbs.archlinux.org/viewtopic.php?id=160187

Or use amixer at boot time to toggle the sound off:
https://askubuntu.com/questions/1040086/choose-whether-to-output-audio-from-speakers-or-headphones


https://unix.stackexchange.com/questions/115302/disable-headphone-jack-detection-in-pulseaudio

 

[levi]

A simple hack might just be buying a short headphone extension lead and plugging that into the headphone port permanently. It's usually a mechanical switch in the headphone port that disables the speakers.

It could theoretically be that switch having lost its spring that makes the speakers pop intermittently, but without opening up the laptop and taking a look that'd be tricky to confirm. I've lost internal sound on my current laptop since the headphone socket decided to crack and implode, which cut off the speakers at the same time for some reason, so now I use a cheap chinese 2.0 USB sound card plugged into a hub that lives on this laptop tray. And I haven't felt the need to take this laptop apart to take a look and that happened over 6 months ago. I should probably take the bottom off this thing and clean it out one of these days anyway.

 

[___]

so it might be the internal switch of the headphone plug? I wonder if a little cleanup might help... but I hadn't thought of that. i think I have a clue now where to start looking.

thanks @levi

let's see if that actually gets me somewhere

 

[___]

Okay I think it's not just the headphone port switch that is causing the problem. Today while testing the port (well actually while booting the laptop, no testing had been done), the popping stopped and turned into a speaker hissing/buzzing that slowly faded out. Then no pops, no nothing anymore. I am almost certain now, that the DAC has died. Well... fuck.

When I get the time to do so, I will open up the device and check for obvious shorts on the audio circuit. Not sure I will be able to find much, but there should be some service manuals by lenovo to help a little at least.

 

[___]

@levi good news! It was the headphone socket after all. I have no clue if it was due to cold solderpoints, but have reflowed the contacts for good measure. Maybe it was just the internal switch being stuck, I don't know but the problem has gone away.

Many thanks for the diagnostics hints, I would have started measuring things in places and probably never thought of the most simple fault to check for first.