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Konami GV (“Baby Phoenix”)

PlayStation 1 hardware in an arcade case (1995-1997). Konami brought Jikkyou Powerful Pro Yakyuu, Hyper Athlete and Dead Eye to it. The game lives on a CD-ROM — but you do not change game by changing the CD, and that is the thing to know.

Identification

Field Value
Manufacturer Konami
Years 1995-1997
Base PlayStation 1, two motherboards depending on the run
CPU CXD8530BQ (ZV610 board) or CXD8530CQ (GV999 board)
GPU CXD8514Q (ZV610) or CXD8561Q (GV999)
Game media CD-ROM
Save / pairing 25C EEPROM
PCB format Konami proprietary

Two motherboards, two generations

The CXD8530BQ + CXD8514Q pair belongs to the ZV610 board; the CXD8530CQ + CXD8561Q pair to the GV999. Working out which one you have is the first thing to do — these are first- and second-generation PS1 chips.

⚠️ The CD does not make the game

This is the platform's quirk, and it catches people out.

Swapping the CD does not change the game

Put another GV game's CD in a machine and it boots — then stops on the error “25C MBAD”.

The reason: the board's 25C EEPROM does not re-initialise when the CD-ROM changes. The CD and the EEPROM are paired. You therefore cannot convert a GV board by simply swapping the disc.

→ The preservation consequence: a GV board separated from its original CD, or whose EEPROM has been erased, will not go back into service on a borrowed disc.

Notable games

Jikkyou Powerful Pro Yakyuu '96 · Hyper Athlete (1996) · Crazy Cross · Susume! Taisen Puzzle-Dama · Beat the Champ · Dead Eye · Weddingr (1997).

Common faults

Symptom Probable cause Next step
“25C MBAD” error CD and EEPROM mismatched Not a fault: see the box above
Will not read the CD worn CD drive (lens, rails) The dominant failure point on any CD machine
No picture CXD8530 / CXD8561 or power PCB diagnosis
Settings lost 25C EEPROM ⚠️ it is also the pairing chip — be careful before touching it

Repair (technician)

  • Do not erase the EEPROM lightly. On this platform it holds the pairing with the CD. Clearing it “to start clean” can leave the board unusable with its own disc.
  • The CD drive is a consumable, as on any machine of that generation. → see the drive method on the disc consoles.
  • PS1 base: the console's failure modes apply to the CPU, the GPU and the power supply.

→ Methods: PCB diagnosis · Recap

Procedure — a dead board, step by step ✅

What this adds

The general method lives in PCB diagnosis. This is its application to this platform: the same order, but with the values actually expected here, so you do not have to go back and forth.

Tools: multimeter, oscilloscope (or frequency counter), current-limited bench supply, desoldering braid. → Tooling

If the board is still in a cabinet

A CRT holds its charge with the machine unplugged. → CRT safety

1. Inspection, power off. Corrosion, cut tracks, oxidised EPROM legs, leaking SMD capacitors, dubious earlier repairs.

2. The connector, before anything else. A large share of "dead boards" are a contact problem, not a fault. Clean the contacts with isopropyl alcohol and reseat — not with an abrasive eraser on a gold edge, which takes the plating off and brings the problem back worse. It costs two minutes and settles the question.

3. Power, measured on the board. Aim for +5.0 V measured as close as possible to where power reaches the board — not at the PSU output: the drop is in the loom, and that is exactly what makes a board boot on the bench and not in the cabinet. Where you probe depends on this board's connector — JAMMA edge, JVS loom or a proprietary harness — plenty of makers kept one long after JAMMA arrived — see Identification above. → Wiring Check −5 V and +12 V too if the sound stage uses them. Suspected short: bring it up current-limited and find the hot spot.

4. /RESET. It must release after power-up. Held low = the CPU never starts. A 1–2 Hz loop is not the reset circuit, it is the watchdog: the CPU is crashing at boot, so look at the bus, not at the reset.

5. Clocks. There is no measurement table for this platform — MAME's sources yield nothing usable for it. Any frequency quoted under Architecture on this page serves as a marker; otherwise compare against a working board rather than against a number: an invented value condemns healthy parts. → PCB diagnosis

6. Bus. Activity on the main CPU's address lines tells you whether it is running or frozen. Frozen with good clocks and good reset → work RAM, bus buffers, ROMs.

7. It boots but the picture or the sound is wrong — that is another job: see Common faults on this page, then signal tracing.

Modernisation & mods

  • ⚠️ Do not host CD images or EEPROM contents — method only.
  • Neighbours: the platform shares its base with the ZN-1/ZN-2 and the G-NET, which also sit on Sony hardware.

Emulation & FPGA

MAME covers the platform (konami/konamigv.cpp, driver by R. Belmont and smf, hardware information recorded by Guru).

Photos / assets

(To take: the two ZV610 and GV999 motherboards side by side if possible, the 25C EEPROM, and the CD drive.)

Archived original documents ✅

Manufacturer documents archived locally, found in Internet Archive's arcademanuals collection on 14 August 2026 and identified from their title page. ⚠️ The items declare no licence.

Sources & attribution

Text (synthesised here; sources listed for attribution):

  • MAME — src/mame/konami/konamigv.cpp (BSD-3-Clause / GPL): the platform known as “Baby Phoenix”, PlayStation 1 based; the CXD8530BQ + CXD8514Q pair on the ZV610 board and CXD8530CQ + CXD8561Q on the GV999; the game list with versions and dates; and above all the finding that swapping CDs between GV games produces the “25C MBAD” error, the 25C EEPROM not re-initialising when the CD-ROM changes — https://github.com/mamedev/mame/blob/master/src/mame/konami/konamigv.cpp

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.