benikigai/ec-1Public

SHA-256 90aeb627cfcc0c5874d972aa56900fdf32565077f4e2edcc9af57a86b7760548

# SYNTHETIC. Same record as in opd.yaml.
id: iss:stick-drift-flux
title: Stick drift traced to flux under the potentiometer
visibility: public
failure_mode: ext:controller:stick-drift
part_types:
- sensor
processes:
- solder
observed_on:
- field
- simulated
detected_at:
- field
- test
conditions: Hand soldering with flux-core wire next to an open potentiometer housing; worse after months of use
yield_impact:
  value: 1.2
  unit: '%'
  source: inferred
  confidence: medium
  evidence:
  - src:reviews
  - src:repair-guide
  note: field return share attributed to drift in the review sample
root_cause:
  value: Flux migrates into the carbon track and changes wiper resistance
  source: inferred
  confidence: medium
  evidence:
  - src:ct-run-1
  - src:repair-guide
resolutions:
- fix_type: design-change
  description: Replace soldered pins with an FPC connector on the stick module
  status: proposed
  operations:
  - op:stick-solder
- fix_type: sop-update
  description: Cap iron dwell at 2 s, no extra flux, inspect with 10x loupe
  status: implemented
  operations:
  - op:stick-solder
  implemented_on: '2026-09-14'
  implementation_evidence:
  - kind: sop-revision
    source: src:teardown-log
    note: SOP A2 rev C, step 3
  yield_before:
    value: 97.8
    unit: '%'
    source: inferred
    confidence: low
  yield_after:
    value: 98.6
    unit: '%'
    source: inferred
    confidence: low
parts:
- part:stick-module
- part:main-pcba
operations:
- op:stick-solder
pfmea:
- fm:stick-flux
tags:
- solder
- field-return