Identify the CD console
Record whether the machine is a front-loading Neo Geo CD, a top-loading Neo Geo CD, or a CDZ. Photograph the underside label, power supply label, video connections and any previous modifications. Case style is a useful first distinction; the actual board revision becomes important when ordering internal parts. The CD machines share a game family with cartridge Neo Geo systems, but an AES or MVS wiring diagram is not a substitute for documentation of this console.
Begin with the original SNK instruction manual. Match the supplied adapter to the console label and regional manual rather than assuming that a connector which fits is electrically suitable. Keep imported equipment's mains requirements in the setup record. A photographed serial number and existing wiring are more useful to a repairer than a seller's description of a unit as simply Japanese or modified.
Build a repeatable baseline
| Test | What to record |
|---|---|
| Startup without a disc | Menu appearance, stable video, sound and controller operation. |
| Known original game disc | Detection, initial loading, a later loading transition and music. |
| Second controller port | Directions and every button separately, using a suitable game. |
| Memory manager | Existing saved data before any deletion or service. |
Use a clean, known-working original disc before treating a recordable disc failure as a drive fault. Write down whether the problem happens on every disc, only after warm-up, or only at a particular transition. Keep discs in cases and inspect them under good light; do not begin by polishing an irreplaceable disc or adjusting the optical pickup. A console that reaches its menu but fails during loading has a different diagnostic starting point from one that never produces a stable menu.
Video and controller checks
Try one documented cable and display path at a time. Check both picture and audio before introducing a scaler or capture device. If the picture fails only through the new equipment, record its settings and cable type before opening the console. Existing CD CSYNC guidance addresses a specific modification, rather than serving as a universal cable recipe. Test a second compatible controller before attributing intermittent directions to the console port.
Choose the next project
The SD Loader maker's compatibility list documents front-loader and top-loader support, while CDZ is not listed as supported. Confirm the exact kit revision before purchase or installation. The revision F front-loader instructions are explicitly model-specific. Continue with drive and loader planning or save, disc and development preservation once the baseline is recorded.