- Be sure that the power is turned on.
- Be sure that the supply voltages are correct and the ground connections are common. For some power supplies, the ‘ON’ button needs to be clicked in order to turn on the output channel.
- Be sure the circuit you built is identical to that in the diagram. Do a node-by-node check if needed.
- Be sure the resistors, capacitors and inductors used in your circuit all have the correct values. You can get that information using a digital multimeter, color code or the nominal value printed on the component.
- Be sure that the equipment is set up correctly and you are measuring the correct parameter.
- If steps 1 through 5 are correct, you probably have used a component that doesn’t work. It is also possible that the equipment does not work (although this is not probable) or the breadboard you are using may have some unwanted paths between nodes. To find your problem you much trace through the voltages in your circuit node by node and compare the signal you have to the signal you expect to have. If they are different, use your engineering judgment to decide what is causing the difference or ask you lab assistant.