Resistor Reads Wrong in Circuit? Troubleshooter

In-circuit readings often lie. Here is why.

Power off and disconnected before measuring resistance. Work through one question at a time. You can go back or start over whenever you like.

Safety: this troubleshooter is general information for low-voltage DC learning circuits. 240V AC mains can kill: in Australia, work on mains wiring must be done by a licensed electrician. Disconnect power before you touch wiring.

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