DC current waveform and no-power triage

What to understand

A bench supply or calibrated current shunt can capture a current-time trace. Probe timing, supply current limit, wiring resistance and sampling rate affect what you see.

A near-zero or stuck-current symptom has many possible causes. Interpret relative changes after the power-button stimulus, paired with rails, USB state and a known-good reference.

A sensor such as INA226 samples with limited bandwidth; it does not capture all fast boot transients. Use suitable instrumentation and note the acquisition limits.

Safe practical workflow

1. Use a protected dummy load to record an idle baseline and triggered rising edge.
2. Log supply voltage, shunt value, sensor calibration, trigger point and sample interval.
3. Annotate three trace regions: pre-trigger, transition and steady/post-trigger.
4. List at least two hypotheses and a safe differentiating measurement for each.

हिंदी में मुख्य बात

करंट की एक fixed value से किसी IC का fault confirm नहीं होता। Trigger से पहले और बाद की waveform, supply setup और दूसरी readings मिलाकर देखें।

Your practical assignment

Attach or sketch a 3-stage current trace with units, instrument limits and next test.

Use the AIFlasher bench worksheet for measured values, observations, unknowns and next tests. A simulated case is acceptable if you do not have the instrument yet.