HomePod No Sound: Dead STM32L Controller

A HomePod that boots, lights up, and responds to Siri but produces no audio at all is a different fault from missing bass. The usual cause is a dead STM32L controller IC. If you have partial audio instead, check no bass first.

No Sound - Dead STM32L Controller IC

Symptoms: Powers on, but there's no sound from any of the speakers.

Diagnosis: If you did your own repairs and suddenly no longer have sound, suspect improper ribbon cable installation, accidental damage, or a short / debris on the amp. On rare occasions, I found the main amp controller had failed. The letters on the "STM32L051C8T7" chip were unevenly worn, note however this isn't always a reliable way to judge condition. I'll add a better way to diagnose this soon.

Repair: "STM32L051C8T7" is available from AliExpress, but we're currently unsure if it needs to be reprogrammed! It's available here. Currently on backorder from mouser and digikey.

Root Cause: Unknown. Pretty rare for the controller to die anyways.

stm chip on amp

Controller Location on Amp Board

Other HomePod Repair Guides

Don't want to attempt it yourself? Mail it in. Repairs average $70 including shipping both ways, with a 12-month warranty.