Boot self-test — automatic, every boot
Boot Schmitt: idle edge count on the flow sensor. 0 = clean; any count means a chattering / cold-soldered trigger — the classic cause of "pump throttles down / won't dispense."
BTS idle: motor-driver current-sense baseline at rest (reference only).
7777 — Test Mode (tap this FIRST)
The master switch and gateway to the others. While it's on, the leak sensor is read every loop so you can watch the leak value react live. Tap again to exit.
5555 — Schmitt / flow-trigger check (Test Mode first)
Idle (pump off): edges must stay 0. Tap/flex the flow-meter & its solder joints — any edge = BAD trigger (re-solder/replace). The idle Y level by itself is not a fault; only edges matter.
Run test: while 5555 is up, hold a normal customer card to run the pump (no sale logged). Good = steady rate with PWM holding; bad = PWM collapsing toward ~275 or flow spiking while the pump bogs down.
6666 — Flow-meter pulse monitor (Test Mode first)
Pass a magnet through the meter by hand (or hold a card to run the pump). Raw should equal pulses — one clean edge per pass; Raw > pulses = contact bounce / jitter.
4444 — Motor-driver (BTS7960) current test (Test Mode first)
Prime the pump with liquid first — a dry pump reads FAIL even on a good driver. It fires a brief pulse and checks the current rises: OK (rise ≥120, driver drove the pump), FAIL (no current → driver/wiring fault, or not primed), FAULT (idle sense pegged high).
2222 — Full self-test (all three at once) (Test Mode first)
One tap runs the pump for ~3 s and checks the driver (4444), flow-meter pulses (6666), and the flow-trigger under real flow (5555) together, then posts an overall PASS / FAIL / PARTIAL here. Prime the pump first — a dry unit reads "no flow / low drive." The individual 4444/5555/6666 cards still work on their own for pinpointing.
Quick map — "won't dispense" / flow looks wrong → 7777 → 5555 (tap the joints at idle, then hold a card for the run test). Pump doesn't drive at all → prime, then 4444. Totals / pricing look off → 6666. Flagged for Schmitt edges at boot → check the Boot Schmitt column, then confirm with 5555 under pump vibration.