Thinkpads Forum

Hello,

First time poster long time occasional lurker. Happy to be here

I recently bought a ThinkPad T400 (647411G) from a good Thinkpad refurbisher on ebay at a discounted price because the sound was listed as not working through the speakers but working through both the headphone jack and bluetooth. When it arrived and I tested the headphone jack, the sound did not work, but the bluetooth still was fine. For this the seller refunded me the whole price of the laptop and said I could keep it(!).

The seller told me he had swapped in several pairs of speakers but that did not work. He also assured me that he had tested the headphone jack with earbuds and it was definitely working when he did test it.

This sound problem also applies to BIOS beeps.

I am currently running a fresh install of Linux Mint 21.3 with Cinnamon. I've also tested it on 32bit Windows 7 and older versions of Mint.

Here is some info about my audio from inxi -F:
I'd be very grateful to hear your thoughts. What do you think might be going on?

UPDATE: It seems like my system thinks the headphone jack is connected even when it's not. I'm going to try and see if I can find a way of fixing that, and see what it does. Any suggestions would be very welcome.

This behavior happens in all three OSes? That would indicate a hardware issue. Is the jack free of debris and you didn't hit the mute button?

Nothing wrong with free.

Nothing wrong with free at all! Though actually I considered it so generous that I swapped him my gargantuan Thinkpad W500 which is way more powerful but also way more broken (won't start).

Definitely not on mute, headphone jack free of debris, same behaviour across OSs and in BIOS.

With the headphone jack it seems to be an additional issue where it cannot identify when it's being plugged in or out. Yesterday it thought it was plugged in when it wasn't. I fired up today and it correctly showed that it was unplugged, but didn't recognise the jack when I plugged it in. I may go over to the Linux Mint forums to see if I can fix that one through the software first.

But with the sound problem in general, yeah, looking like a hardware issue, how can I find out more? My neighbour said it's probably a sensor on the Motherboard?

To get some more T400 info, read this overview by McDonnell.
Get a free T400 schematic here.
I just had a thought: remove the wifi card and the bluetooth card, then try the sound again.

Wow go raibh míle maith agat! I am a little overwhelmed at the moment but will report back after getting some time to try this. I just experimented with the wifi/bluetooth kill switch and rebooted and it didn't work but I guess you would have suggested that instead if you thought it made a difference

I just tried removing bluetooth and wifi quickly while I had my tools out working on something else.

I haven't resolved the headphone detection issue and this time the computer thought the headphones were plugged in (whether they were or not) so felt like i could only test the headphone jack output. I plugged some headphones in and no sound. Volume at max.

Will try and see if I can learn anything more about the headphone jack detection over on the Linux Mint forums and see if i can resolve that before coming back to this.