Flash failed

## Bug Report - flash.comma.ai

**Device:** comma four
**Serial:** 809f95d4
**Error:** FLASH_SYSTEM_FAILED
**Step:** FLASH_SYSTEM
**Last Message:** Flashing system_a

**OS:** Windows 10/11
**Sandbox:** None detected
**Browser:** Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/151.0.0.0 Safari/537.36
**URL:** https://flash.comma.ai/
**Time:** 2026-08-20T04:51:08.228Z

Console Logs

```
[2026-08-20T04:25:19.673Z] [info] [qdl] Flashing qupfw_b
[2026-08-20T04:25:19.689Z] [info] [Flash] Downloading splash
[2026-08-20T04:25:19.695Z] [debug] [ImageManager] Downloading splash from https://commadist.azureedge.net/agnosupdate/splash-5c61260048f22ede6e6343fabb27f6ff73f9271f4751a01aaf7abf097afc1f08.img.xz
[2026-08-20T04:25:21.390Z] [info] [Flash] Flashing splash
[2026-08-20T04:25:21.488Z] [info] [qdl] Flashing splash
[2026-08-20T04:25:22.595Z] [info] [Flash] Downloading storsec
[2026-08-20T04:25:22.603Z] [debug] [ImageManager] Downloading storsec from https://commadist.azureedge.net/agnosupdate/storsec-4494d86f68b125fbf2c004c824b1c6dbe71e61a65d2a1cc7db13c553edcb3fce.img.xz
[2026-08-20T04:25:22.827Z] [info] [Flash] Flashing storsec_a
[2026-08-20T04:25:22.923Z] [info] [qdl] Flashing storsec_a
[2026-08-20T04:25:22.936Z] [info] [Flash] Flashing storsec_b
[2026-08-20T04:25:23.026Z] [info] [qdl] Flashing storsec_b
[2026-08-20T04:25:23.039Z] [info] [Flash] Downloading tz
[2026-08-20T04:25:23.047Z] [debug] [ImageManager] Downloading tz from https://commadist.azureedge.net/agnosupdate/tz-e9443bf187641661bfa6c96702b9ab0156e72fb7482500f8799ba9ee2503cb16.img.xz
[2026-08-20T04:25:24.367Z] [info] [Flash] Flashing tz_a
[2026-08-20T04:25:24.470Z] [info] [qdl] Flashing tz_a
[2026-08-20T04:25:24.550Z] [info] [Flash] Flashing tz_b
[2026-08-20T04:25:24.640Z] [info] [qdl] Flashing tz_b
[2026-08-20T04:25:24.718Z] [info] [Flash] Downloading boot
[2026-08-20T04:25:24.722Z] [debug] [ImageManager] Downloading boot from https://commadist.azureedge.net/agnosupdate/boot-8806802b195a5b1396a3ae8dd92a8b7711dc522f6aceafd820e871bae5c8a6d8.img.xz
[2026-08-20T04:25:26.953Z] [info] [Flash] Flashing boot_a
[2026-08-20T04:25:27.062Z] [info] [qdl] Flashing boot_a
[2026-08-20T04:25:27.647Z] [info] [Flash] Flashing boot_b
[2026-08-20T04:25:27.750Z] [info] [qdl] Flashing boot_b
[2026-08-20T04:25:28.338Z] [info] [Flash] Downloading system
[2026-08-20T04:25:28.343Z] [debug] [ImageManager] Downloading system from https://commadist.azureedge.net/agnosupdate/system-ef0d879302cb29e72110e9c8d3f947c830fd7d37c8192744fc9dbea1af78501f.img.xz
[2026-08-20T04:50:43.741Z] [info] [Flash] Flashing system_a
[2026-08-20T04:50:43.744Z] [error] [Flash] An error occurred while flashing system
[2026-08-20T04:50:43.745Z] [error] {}
[2026-08-20T04:50:43.747Z] [debug] [Flash] error 7
[2026-08-20T04:50:43.749Z] [info] Flashed system in 1657.67s
```

Start at https://flash.comma.ai/ and reproduce the FLASH_SYSTEM_FAILED report on a comma four using Windows 10/11. Trace the console logs through the system download and the failing system_a flash step, then determine what evidence distinguishes the failure from the reported error 7. Done means system_a completes successfully or the failure is reported with an actionable cause.

Written by the indexing model from the issue text.