Welcome. This is a picture-oriented guide for diagnosing issues with Commodore 64 computers - basically an image gallery of various problem scenarios along with their descriptions and known causes. Use this guide as a tool to assist in diagnosing C64 issues, to get a general idea of what might be wrong with your machine. Keep in mind that it's rare to find an exact match and sometimes multiple different problems can cause a similar faulty screen. This site focuses on the classic breadbin models, though many of the fault scenarios are also applicable to newer revisions such as the C64C. For the best results, use this guide in conjunction with the other C64-related sites listed here.
Since audio problems are difficult to portray with pictures, here is a separate section for them.
The site will always be a work in progress, more pictures will be added as they become available. If you have a picture to contribute or questions about the currently listed problems/causes, feel free to contact me:
Best of luck in bringing these legendary old computers back to life!