DSC-BRAIN USER GUIDE · TROUBLESHOOTING

Probe dark or faulted

Probe not reporting vs channel fault vs out of service; what steering does meanwhile; power, Wi-Fi, cable and calibration checks; judging a probe by its watering response.

  verified for 9.0.0 · firmware train 8.2.0.0

  last verified 2026-09-17 · mirrored 2026-09-15

Three different states

Shown Means Steering
Out of service You told the brain not to expect it Withheld, no alert
Probe not reporting (warn after 15 min) In service, no readings Withheld; the plant reads grey; the mat loses that vote
Channel fault (warn) Reporting, but a channel is frozen, railed or drifting from its peers That channel withheld; the others still used

A dark in-service probe reads offline, it does not vanish from the desk.

On probe firmware 8.2.0.0 every answered Modbus read marks the probe online, so a probe whose readings are moving no longer shows a standing Sensor Fault with Modbus Probe Online: off. A probe still on older firmware can show that pair while it reads normally; trust the readings and the watering response below.

Not reporting: checks

  1. Power and LED on the probe.
  2. It joined the fleet Wi-Fi: on the hub portal's Devices list, or on the ESPHome dashboard as online.
  3. The seat's host name or IP in Settings › Devices matches what the router gave it.
  4. If it just came back, the brain is in its probe back fast window; give it a minute.

Channel fault: checks

  1. Frozen: the sensor head is unplugged from the probe board (RS485 cable) or in air. Reseat the cable.
  2. Railed: a reading at a bound (moisture 100 %, EC 0). Usually a wet connector or a probe in free water.
  3. Drifting from peers: compare with the other probe in similar substrate. Run Soft calibrate (tap water → after water) or a Lab wet calibration if EC or pH is off by a constant.

Judge by the watering response

A probe is good if moisture steps up on a watering and dries back over the following days. Fault flags describe a moment; the response describes the probe. Log a Water entry and watch the Dryback chart (the probe shows READING FAST for a while after a logged watering).

Replacing

Flash the replacement with the same role, update the seat's host, recalibrate. The plant keeps its slot and journal.

DSC-Brain user guide · Probe dark or faulted · this page is edited on the site; the Notion original was retired after the mirror