Practical Electronics/Common Problems

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it's not's working yet[edit]

it used to work, but no more[edit]

If it works once, most electronic devices will continue to work almost indefinitely. There are a few exceptions:

  • nearly every electronic component will be permanently damaged or destroyed, if power or other connections are connected to something with a voltage too large to handle, or unexpectedly reversed. Designers often put a "protection circuit" -- such as a crowbar circuit -- between connectors and sensitive components. But with adequate protection, most components will last indefinitely:;
    • transistors
    • integrated circuits
    • ceramic capacitors
    • printed circuit boards
  • Some things, even when used normally, will eventually wear out and stop working:
    • primary batteries
    • secondary batteries
    • incandescent bulbs
    • LED degradation: every LED (including the infrared LED in each opto-isolator) gradually gets dimmer and dimmer.
    • aluminum electrolytic capacitors ("wet electrolytics").
    • relays

High temperature and high current usually accelerates wear-out. Sometimes a heat sink can extend the life of a component.