Commodore 64

The Commodore 64 is an 8 bit computer sold by Commodore International, and the single highest-selling home computer of all time. It uses a keyboard-centric form factor, commonly referred to as the "breadbin".

Causes
On some models of the original external power supply (those models most common in North America) the voltage regulator on the 5V DC output fails routinely, producing a large voltage spike that fries the chips on the C64's mainboard.

Solutions

 * Only use a modern aftermarket power supply at all costs (the original power brick is virtually impossible to repair on account of Commodore filling the housing with epoxy)
 * If using an original power supply then an over-volt protector, such as a Commodore Saver from Ray Carlson, should be used.
 * A new power supply can be built with minimal effort using a small prebuilt 5VDC supply and a 9VAC transformer. Dave Farquhar has an easy guide on how to do this.

Causes
Due to the way the C64's logic is structured, a fault in any of a number of chips can cause unusual display output. The Pictorial C64 Fault Guide is a great starting point for diagnosing these issues.

Solutions
If you are still unsure which chip is causing the problem, you can brute force a diagnosis by swapping chips from a donor machine until the problem is fixed. If you find a new fault/solution, consider adding it to the wiki or submitting it to the Pictorial Guide.

Disassembly Notes
Warnings or tips to disassemble then device

Basic PCB Name
Note model numbers and board revisions down here

Individual Components
If parts are not available or different selection is preferred, you can use the values in the Original Parts section to perform a parametric search.

Kits

 * Digikey BOM: https://www.digikey.com/

Related Links

 * The Pictorial C64 Fault Guide