Editing Amstrad CPC 464 Troubleshooting Guide (section)

=== No display / garbage screen ===

* Reseat the '''Z80''' and the '''gate array (40007)''' &mdash; both are common failure points, and a socket contaminated with old thermal paste has been found preventing operation. Confirm the TTL logic is seeing its 5&nbsp;V rail before condemning a chip.<ref name="cpc">Dorey, Andrew. [https://andrewdorey.com/post/amstrad-cpc-464-repair "Amstrad CPC 464 Repair and Restoration"]; and [https://retrohax.net/cpc-464-repairs-and-restoration/ "CPC 464 &mdash; Repairs and restoration"], retrohax.net. Source for the Z80/gate-array (40007) failure points, thermal-paste-fouled socket, monitor-connector corrosion, dried power-socket joints, power-switch debris, and cassette idler/belt faults.</ref>
* Corrosion at the monitor connector can pull down the video signal; desolder-inspect and clean it.<ref name="cpc">Dorey, Andrew. [https://andrewdorey.com/post/amstrad-cpc-464-repair "Amstrad CPC 464 Repair and Restoration"]; and [https://retrohax.net/cpc-464-repairs-and-restoration/ "CPC 464 &mdash; Repairs and restoration"], retrohax.net. Source for the Z80/gate-array (40007) failure points, thermal-paste-fouled socket, monitor-connector corrosion, dried power-socket joints, power-switch debris, and cassette idler/belt faults.</ref>