LED does not light
Check polarity, resistor, voltage and connection continuity.
Troubleshooting
Structured fault-finding instead of random part replacement.
Start by disconnecting power safely, then inspect the circuit methodically.
First value: every tool works without an account, and guides link directly to calculations.
All pages in this category
Circuit overheating
A method to locate excessive current and power loss.
Noisy signal
Decoupling, grounding, wiring and noise sources.
Voltage drops under load
Separate a weak supply from cable and connector losses.
Solder bridges
Remove excess solder without damaging pads or parts.
Microcontroller keeps resetting
Power supply, brownout, noise and shared loads.
Battery drains too fast
Current measurement, sleep modes and hidden converter losses.
Resistor reads a different value
Effects of in-circuit paths, tolerance and probe contact.