How to Debug Circuits
- Check components
- Plugged in?
- Power switch?
- Fuses?
- Loose connections?
- Is anything hot?
- Does anything smell funny?
- Do all cables conduct?
- Trace voltages
- Label schematic with expected voltages
- Starting with the power supply, test critical points
- Check voltages along high-current wires
- Noise?
- Noise happens when something vibrates
- Oscillations?
- Oscillations are caused by feedback, capacitors and
inductors.
- Add resistance where it shouldn't matter
- Add capacitance where it shouldn't matter
- Break feedback loops
- What's the power supply voltage/bandwidth/slew rate/current limit
on that?
- What's the power rating on that?
- How long are your wires?
- Laying on of hands
- More capacitors on power lines?
- Wiggle connections.