Hardware · October 18, 2026
Giving a Samsung HW-FM35 a Random playback default
A firmware patch makes Random the startup default for USB music on my Samsung HW-FM35/ZA. The first song stays the same; subsequent tracks play randomly.
I wanted my Samsung HW-FM35/ZA soundbar to start USB music in Random mode without having to select it each time. We now have a working firmware patch for that.
Use at your own risk. This unofficial patch is provided as is, without any warranty. I accept no responsibility for hardware damage, an unusable device, data loss, or other harm resulting from its use. You are responsible for deciding whether to install it and for any consequences.
After flashing it on my soundbar, the first song still plays first, but the songs after it play randomly. That is fine for what I wanted. This is a startup default change; it does not save whichever Repeat mode was last selected.
The patch and instructions are now available on GitHub:
What the patch changes
The soundbar has separate controller and playback-processor firmware. This patch changes the backend playback initialization, setting the internal playback mode and the reported mode to Random. It leaves the controller firmware stock.
Five instructions change, totaling six bytes in the decoded program. Because that code is compressed, rebuilding the section changes much more of the final ROM. The patcher also restores the firmware file's checksum.
The public download contains a Python patcher and the patch instructions. You supply Samsung's official ROM; the tool checks its exact SHA-256 and will only save the exact modified image that was tested on my unit. It does not flash anything by itself.
What has been tested
My soundbar identifies as HW-FM35/ZA, with M 1004.1 and D 1006.0. An official stock USB reinstall worked before the modified firmware was tried. The modified firmware then worked, with the fixed first song followed by random playback.
Offline checks also covered the nine compressed sections, initialization, the firmware's checksum and filename helpers, and the stock controller's Repeat-mode handling. Some tests use simulated file metadata and RNG inputs; those are not substitutes for hardware testing.
Before trying it
This is an unofficial experimental patch, reported working on one soundbar. Other models or firmware versions are not validated. An interrupted update or failed boot can leave the unit unusable and require opening it for recovery. A normal stock USB reinstall is not a guaranteed rescue if the modified firmware cannot boot.
Read the complete project instructions, verify the hashes, and keep the official firmware separate. The first song staying the same is a known behavior, not a promise of a different opening song on every power-up.