Repair

An advanced-technician section: cross-cutting methods (recap, fault-finding, soldering, EPROM, HV safety) and focused guides (monitors, PSUs). Per-machine procedures also live on their console / PCB / cabinet pages (links at the bottom).

Methods & workbench (cross-cutting)

• Tools & workbench — irons, hot air, multilayer desoldering, scope, current-limited PSU, isolation transformer, programmer.
• Recap: general method — ESR diagnosis, SMD removal without ripping pads, electrolyte cleanup, choosing caps.
• Arcade PCB fault-finding — no-boot, watchdog, clock/reset, signal tracing, substitution, fault patterns (RAM/ROM/customs/sound).
• Trace, via & reflow repair — corrosion, bridges, eyelets, reflow/reball of customs.
• Backup batteries — Varta/NiCd leaks and suicide (CPS-2/FD1094 keys): two opposite problems.
• EPROM: read, burn & reproduce — densities → 27Cxxx, dump/checksum, epr-/mpr-, replacing a blown EPROM.
• CRT safety & HV discharge — anode, hot-chassis, isolation transformer (read before any monitor work).

Monitors (CRT)

• Nanao MS8 — Sega candy cabs (Astro City), 15/24 kHz.
• Nanao MS9 — New Astro City, Blast City…
• Nanao MS2930–MS2933 (tri-sync) — 31 kHz candy (New Net City, Naomi Universal).
• Sanwa — PM-1723/PM-1745, 20I16, 29E31S tri-sync (JP cabs).
• Wells-Gardner — US cabs (K4600/K4900/K7000, D9200, 6100 vector).
• Sanyo 20-EZ — US cabs (20-EZ / 20-EZV Nintendo): 160 V recap, vertical collapse, PCB cracks.
• Hantarex — EU cabs (MTC-9000, Polo / Polo 2).
• Toshiba PB-7534 — Konami Windy 2 (tri-sync; bipolars + 4 separate filters).
• Modern tri-sync — Wei-Ya / Makvision / Kortek (15/24/31 kHz auto, VGA): weak HOT, recap, lead-free solder.
• Other chassis & equivalents — Toei, Neotec, Rodotron/Pentranic, universal Wei-Ya + swap table.

Power supplies

• Sega PSU (candy cab) — +5/+12/−5 V, +5 V adjustment, recap.
• See also the wiring/power page (mains chain, DC distribution, connectors).

Procedures embedded in machine pages

• Mega Drive recap (all revisions).
• CPS-2 suicide / de-suicide.
• System 16 de-suicide (FD1094).
• CDTV / Amiga Varta battery.
• Every console / PCB / cabinet page has its Common faults / Repair section.

Review & corrections

How this space is used

Spotted a wrong value, an outdated procedure, a chip reference that does not match your board? Say so here, with what you observed (model, board revision, serial number, measurement). Every report is cross-checked against a source before anything changes — an unverifiable correction is published as “reported by …, not cross-checked” rather than silently applied.

Reading is open to everyone; posting requires signing in with Discord. Reports from the wiki's declared reviewers are handled first; anyone else's are read too, but go through a human before anything is changed.