festoon

The permanent lights run WLED on a QuinLED ESP32 board, and it will not stay reliably powered. It drops, it comes back, sometimes it needs a physical power cycle. For a show that has to run unattended in the cold every night in December, that is the whole problem.

Diagnose before rebuilding

The instinct is to build a replacement, and that's probably where this ends up. But building something new is only a fix if I know what failed, and right now I don't. Swap the board, have it still drop out in February, and I've learned nothing while spending a weekend.

The candidates, roughly in order of how likely I think they are:

• Brownout under load. The ESP32 resets when the rail sags. Long pixel runs draw far more current at full white than the arithmetic suggests, and a supply sized for average draw dies on peaks.
• Insufficient power injection. Voltage drop along the run means the far end is dim and the near end is fine, but the resulting current draw profile can also drag the controller's own supply down with it.
• Wi-Fi power management. The ESP32 sleeping its radio and failing to come back cleanly looks identical to a power fault from the outside.
• Cold and condensation. It's outdoors. Enclosure temperature swings and moisture ingress are real, and they're seasonal in a way that would explain a lot.
• The supply itself. Cheap PSUs degrade, and they degrade first under exactly the conditions this thing runs in.

What'll actually tell me

Instrumentation before parts. Voltage logged at the controller and at the far end of the run, uptime and reset reason reported to Home Assistant, and enclosure temperature alongside both. WLED already exposes enough to correlate a reset against what the show was doing at the time.

Once there's a graph, the rebuild designs itself: correctly sized supply, injection at the right intervals, a proper enclosure, and a board chosen for the load rather than for what was in the drawer.