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benikigai/ec-1Public

EC-1 Wireless Controller

Synthetic example. Every value is made up to show the format.

Lessons · Risk

Risk

What could go wrong, and how badly?

12
failure modes
245
top RPN: Flux residue wicks into stick potentiometer
2
with RPN 100 or more
1122334455667788991010How likely (occurrence) →How bad (severity) →Flux residue wicks into stick potentiometer · severity 7, occurrence 5, detection 7 · score 2451Battery connector half-seated · severity 8, occurrence 4, detection 6 · score 1922Battery placed off-pocket · severity 9, occurrence 2, detection 5 · score 903Battery wire pinched between shells · severity 9, occurrence 2, detection 5 · score 90Cold or cracked solder joint on stick pins · severity 7, occurrence 3, detection 4 · score 84Shoulder gap over 0.30 mm · severity 4, occurrence 5, detection 4 · score 80Board pressed onto its ledges cracks a support rib · severity 5, occurrence 2, detection 6 · score 60Screw strips the boss · severity 5, occurrence 3, detection 3 · score 45Low radiated power · severity 6, occurrence 3, detection 2 · score 36Calibration out of range · severity 4, occurrence 4, detection 2 · score 32LRA connector mated off by one pin · severity 5, occurrence 2, detection 3 · score 30Label serial does not match the unit · severity 4, occurrence 2, detection 3 · score 24
  1. 1Flux residue wicks into stick potentiometer · 245
  2. 2Battery connector half-seated · 192
  3. 3Battery placed off-pocket · 90
Bigger dots are harder to catch (detection). Red and numbered: the three highest risk scores (severity × occurrence × detection). The shaded corner is likely and bad.
Risk score (severity × occurrence × detection) per failure mode, highest first.
RPNSODFailure modeEffect and causeOperation
245757Flux residue wicks into stick potentiometer
fm:stick-flux		Stick drift in the field
Cause: Too much flux, iron dwell over 3 s
Evidence: src:repair-guide, src:reviews
Hand-solder stick module to the PCBA (6 pins)
192846Battery connector half-seated
fm:battery-unseat		Dead unit after drop
Cause: No seat check, tight z-height under the top shell
Evidence: src:ct-run-1, src:reviews
Mate battery connector
90925Battery placed off-pocket
fm:cell-misplace		Pinched cell at close, swelling risk
Cause: No locating feature for the cell
Evidence: src:ct-run-1
Stick battery into pocket with PSA
90925Battery wire pinched between shells
fm:pinched-wire		Short, field return, safety
Cause: Wire routed over the boss
Evidence: src:ct-run-1
Close top sub-assembly onto the core
84734Cold or cracked solder joint on stick pins
fm:stick-cold-joint		Intermittent stick axis
Cause: Iron temperature or dwell too low
Evidence: src:ct-run-1
Hand-solder stick module to the PCBA (6 pins)
80454Shoulder gap over 0.30 mm
fm:gap-high		Cosmetic complaint, dust ingress
Cause: Shell warp at the shoulder wall
Evidence: src:caliper-run-1, src:reviews
Cosmetic and gap check
60526Board pressed onto its ledges cracks a support rib
fm:pcba-boss-crack		Loose PCBA, rattle
Cause: Press force not controlled
Evidence: src:teardown-log
Snap PCBA into bottom shell
45533Screw strips the boss
fm:screw-strip		Loose shell, gap
Cause: Torque too high or cross-threaded
Evidence: src:teardown-log
Drive four M2 screws to 0.18 N·m
36632Low radiated power
fm:rf-low		Short range in the field
Cause: LRA placed against the antenna keep-out
Evidence: src:eol-sample
Flash the test image, then RF test
32442Calibration out of range
fm:stick-cal-fail		Rework or scrap
Cause: Stick module centre offset beyond 4%
Evidence: src:eol-sample
Stick centre and range calibration
30523LRA connector mated off by one pin
fm:haptic-reversed		No haptics
Cause: Unkeyed 2-pin connector
Evidence: src:teardown-log
Place LRA and mate its connector
24423Label serial does not match the unit
fm:wrong-label		Traceability lost
Cause: Label printed ahead of unit
Evidence: src:teardown-log
Apply rating label