Talk:PinePhone Hardware Issues

Evidence for/against the shim U101 fix

Works for me 2024-11-06

I shimmed my U101 per the advice given here. Based on two days of a small handful of tests, and after having earlier had a variety of audio and non-audio bugs on my PinePhone v1.2b running Mobian/trixie, including this difficult-to-reproduce bug, my microphone appears to be working. I now have out-of-the-box alsa-ucm-conf 1.2.12-1mobian1 and other packages at the Mobian default, with modem: FLOSS firmware 0.7.2 + ADSP 30.006.30.006. Boud (talk) 13:49, 6 October 2024 (UTC)

However, the out-of-the-box alsa-ucm-conf parameters still give bad audio quality as heard on the remote phone for phone calls "out in the field" as opposed to between people in nearby quiet rooms. This VoiceCall.conf file (commit `cf82dfb455`), with the microphone U101 shimmed, has worked fine on several real-world tests. Boud (talk) 00:52, 1 November 2024 (UTC)

Speculation about why the shim U101 fix may work

Any proper explanations? Some hypotheses include:

• electrical isolation/contacts:
  • the shim improves an electrical contact that was too weak (not contacting properly); or
  • prevents some weak electrical contact that causes current to go in the wrong direction.
• sound wave air transmission:
  • the shim pushes the microphone slight higher above the back of the phone in order to better match the hole in the chassis.

Boud (talk) 13:49, 6 October 2024 (UTC)

I've updated the above list based on a matrix chat favouring "improving an electrical contact". Boud (talk) 17:52, 8 October 2024 (UTC)