If you have connected everything correctly but the circuit still isn’t working as expected, there are usually only two possibilities: **one or more components are damaged, or something is connected incorrectly.** In my experience, the second one is much more common. Even when I’m careful, I still sometimes connect something to the wrong hole on a breadboard because the holes are so small and closely spaced. Before assuming that a component is broken, **double-check the following:** 1. **Are all the wires and component terminals connected to the correct breadboard holes?** Breadboard holes are small and densely arranged, so it’s very easy to accidentally plug a wire or component into a hole next to the one you intended. Carefully trace each connection and compare it with your circuit diagram. 2. **Is the capacitor connected with the correct polarity?** Some capacitors, such as electrolytic capacitors, have polarity. If you have a black cylindrical capacitor, look for the **+ and − markings** on its body. Make sure it is connected in the correct direction. In a typical circuit, the **negative (−) terminal is connected to ground**. 3. **Did you identify the correct transistor terminals?** A transistor has three terminals: **collector, base, and emitter**. However, their physical arrangement is **not always the same from one transistor to another**. A good practice is to check the transistor’s **datasheet** before connecting it. Search for the exact transistor part number followed by “datasheet,” find the manufacturer’s PDF, and look for the **pinout** diagram. This will tell you exactly which physical pin is the collector, base, and emitter. 4. **Did you check the component values?** Make sure you are using the correct resistor and capacitor values. For resistors, you can use a multimeter to measure the resistance and confirm that you have the correct value before connecting it to the circuit. The same applies to capacitors. The capacitance value may be printed directly on the capacitor, or it may be shown as a code. For example, if you see a code such as **104**, you can look it up online to find its capacitance value. Don’t assume that two capacitors that look the same have the same value—always check the markings. Taking a few extra minutes to double-check these connections can save you a lot of time troubleshooting a circuit that appears to be “broken.”